Prognosis prediction method for metastatic hormone-sensitive prostate cancer

Abstract

The problem addressed by the present invention is to provide a testing method that makes it possible to predict a prognosis for metastatic hormone-sensitive prostate cancer, which has a high possibility of a bad prognosis, via a means capable of being applied in a clinical setting.　The present invention relates to a testing method for prognosis prediction for metastatic hormone-sensitive prostate cancer, including a step for measuring the expression level of one or two genes selected from among an androgen receptor gene and an osteoglycin gene, or the expression level of a transcription product thereof, in prostate tissue collected from a metastatic hormone-sensitive prostate cancer patient.

Description

Prognostic prediction methods for metastatic hormone-sensitive prostate cancer

[0001] The present invention relates to a method for predicting the prognosis of metastatic hormone-sensitive prostate cancer.

[0002] Prostate cancer is the second most common tumor in men and the fifth leading cause of cancer-related deaths. While most men are diagnosed with curable disease, recent epidemiological data suggest an increasing incidence of metastatic prostate cancer. The durability of metastatic hormone-sensitive prostate cancer (mHSPC) treatment is highly variable and difficult to predict. Clinical indicators, such as Gleason score, tumor stage, and PSA concentration, have been used in various combinations to predict disease outcomes. However, these prognostic indicators do not accurately predict clinical outcomes for individual patients. Improved prognostic biomarkers are needed to determine which patients will benefit from more aggressive treatment and which patients can be spared unnecessary and harmful therapeutic interventions.

[0003] Several groups have attempted to develop tumor-derived RNA expression markers to improve the predictive power of clinical indicators. However, no model has been established to predict cancer-specific survival (CSS) in mHSPCs. The present inventors successfully extracted high-quality RNA from paraffin-fixed prostate needle biopsy specimens using laser microdissection (a procedure in which cancer tissue is excised with a laser scalpel under microscopic observation and RNA is extracted). Using two independent cohorts, they verified that 10 androgen / estrogen signaling and stem cell marker genes are associated with survival prognosis (Non-Patent Document 1). However, laser microdissection is complex and time-consuming, making its application in clinical settings difficult. A method for determining the likelihood of cancer recurrence in prostate cancer patients by measuring the expression levels of multiple microRNAs has also been reported (Patent Document 1).

[0004] JP 2018-68299 A

[0005] Clin Cancer Res. 2014;20(17):4625-35.

[0006] However, although Non-Patent Document 1 was able to classify the life prognosis of mHSPCs into three stages (good, intermediate, and poor), it was not able to accurately predict survival rates. Furthermore, as mentioned above, the laser microdissection method employed in the method described in Non-Patent Document 1 is a complicated procedure, making it difficult to apply in routine clinical settings. Therefore, an object of the present invention is to provide a testing method that can predict the prognosis of metastatic hormone-sensitive prostate cancer, which is likely to have a poor prognosis, using means that can be applied in clinical settings.

[0007] Therefore, the present inventors conducted research to find a biomarker that can be measured by means applicable in clinical settings, and found that patients with low expression levels of one or two genes selected from the androgen receptor gene and the osteoglycin gene in prostate tissue collected from patients with metastatic hormone-sensitive prostate cancer are likely to have a fatal prognosis, and thus completed the present invention.

[0008] That is, the present invention provides the following inventions [1] to

[12] . [1] A testing method for predicting the prognosis of metastatic hormone-sensitive prostate cancer, comprising the step of measuring the expression levels of one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcription products, in prostate tissue collected from a patient with metastatic hormone-sensitive prostate cancer. [2] The testing method according to [1], comprising the step of measuring the expression levels of two genes, the androgen receptor gene and the osteoglycin gene, or their transcription products. [3] The testing method according to [1] or [2], further comprising the step of comparing the measured expression levels with reference values ​​for the genes or their transcription products to provide information for predicting the prognosis of metastatic hormone-sensitive prostate cancer. [4] The testing method according to any of [1] to [3], wherein the expression level of the gene or its transcription product is the expression level of mRNA. [5] The testing method according to any of [1] to [4], wherein the expression level of the gene or its transcription product is measured by PCR, Northern blot hybridization, or microarray. [6] The test method according to any one of [1] to [5], wherein the expression level of the gene or its transcription product is measured by RT-PCR. [7] A companion diagnostic method based on the test according to any one of [1] to [6]. [8] A prognosis prediction reagent for metastatic hormone-sensitive prostate cancer, comprising an oligonucleotide that specifically hybridizes to one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcription products, or fragments thereof. [9] The reagent according to [8], comprising a primer set for amplifying one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcripts, or fragments thereof, or a probe that specifically hybridizes to one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcription products, or fragments thereof.

[10] The reagent according to [8] or [9], comprising a primer set for amplifying one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcripts, or fragments thereof.

[11] The reagent according to any one of [8] to

[10] , which uses two genes, i.e., an androgen receptor gene and an osteoglycin gene, or a transcription product thereof, or a fragment thereof.

[12] A companion diagnostic agent containing the prognosis prediction reagent according to any one of [8] to

[11] .

[0009] The testing method of the present invention makes it possible to predict the prognosis, particularly the likelihood of death, of patients with metastatic hormone-sensitive prostate cancer, and is useful for formulating treatment guidelines.

[0010] Figure 1 shows a nomogram predicting 1-, 3-, and 5-year cancer-specific survival rates for mHSPCs. Figure 2 shows Kaplan-Meier curves showing the relationship between AR (A) and OGN (B) expression levels and prostate cancer-specific survival rates.

[0011] In the present invention, the terms "nucleic acid" and "polynucleotide" refer to DNA, RNA, or fragments thereof. DNA includes cDNA, genomic DNA, and synthetic DNA, and "RNA" includes total RNA, mRNA, rRNA, tRNA, non-coding RNA, and synthetic RNA.

[0012] In the present invention, the term "gene" includes double-stranded DNA including human genomic DNA, single-stranded DNA (positive strand) including cDNA, single-stranded DNA (complementary strand) having a sequence complementary to the positive strand, and fragments thereof, and refers to DNA containing some biological information in the sequence information of the bases constituting the DNA. Furthermore, the term "gene" in the present invention includes not only "genes" represented by a specific base sequence, but also their homologs (i.e., homologs or orthologs), variants such as genetic polymorphisms, and derivatives. The names of genes disclosed herein are based on the official symbols listed in NCBI ([www.ncbi.nlm.nih.gov / ]).

[0013] In the present invention, the "transcription product" of a gene refers to RNA produced by transcription from a gene (DNA).

[0014] One aspect of the present invention is a testing method for predicting the prognosis of metastatic hormone-sensitive prostate cancer, which comprises a step of measuring the expression levels of one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcription products, in prostate tissue collected from a patient with metastatic hormone-sensitive prostate cancer.

[0015] The subjects of the test in the present invention are patients with metastatic hormone-sensitive prostate cancer (mHSPC). Here, "metastatic" refers to a patient diagnosed with distant metastasis to bone, lung, liver, etc., or distant metastasis to lymph nodes other than the pelvis (such as the neck, mediastinum, or abdomen) by computed tomography or bone scintigraphy. Furthermore, "hormone-sensitive" refers to the state before medical or surgical androgen deprivation therapy (ADT). Specifically, this refers to a patient who has received antiandrogen therapy or surgical castration. Furthermore, a prostate cancer patient refers to a patient whose prostate biopsy pathologically reveals adenocarcinoma.

[0016] The biological sample used in the present invention is prostate tissue collected from a patient with metastatic hormone-sensitive prostate cancer. The prostate tissue can be collected using a conventional tissue collection needle. The collected tissue may be frozen and stored, or may be fixed in formalin for histopathological examination.

[0017] The subject of measurement in the testing method of the present invention is the expression level of one or two genes selected from the androgen receptor gene and the osteoglycin gene or their transcription products. That is, the expression level of one or two genes (DNA) selected from the androgen receptor gene and the osteoglycin gene or their transcription products (RNA). Furthermore, the expression level refers to the expression amount of the gene or its transcription product. The subject of measurement is preferably the RNA expression amount of one or two genes selected from the androgen receptor gene and the osteoglycin gene, and more preferably the mRNA expression amount of one or two genes selected from the androgen receptor gene and the osteoglycin gene.

[0018] Androgens play an important role in the development and progression of prostate cancer. Androgens bind to androgen receptors (ARs), a type of nuclear receptor present in prostate cells, and enter the cells. They then cooperate with AR transcriptional cofactors to bind to androgen receptor-binding sequences in the promoters and enhancers of target genes, regulating gene expression. AR is expressed in most prostate cancer cells. Furthermore, it has been reported that 90% of prostate cancers have androgen-dependent growth potential at the start of treatment. Therefore, endocrine therapy plays an important role in prostate cancer. Our results suggest that reduced AR expression in prostate needle biopsy specimens may result in shorter cancer-specific survival (CSS) in patients with mHSPC. It is important to confirm AR expression before initiating treatment.

[0019] Osteoglycin (OGN) is a type of proteoglycan. In vitro studies suggest that it inhibits bone formation. Furthermore, OGN is widely expressed not only in muscle and bone but also in various organs, and its contribution to various malignant diseases has been demonstrated. Several reports have been published on the relationship between OGN and cancer. However, there have been no reports on its relationship with mHSPCs. Our results suggest that low OGN expression in prostate needle biopsy specimens in patients with mHSPCs may result in shorter CSS.

[0020] The gene or its transcription product can be measured by PCR, Northern blot hybridization, or microarray. Among these, PCR is particularly preferred from the viewpoint of enabling measurement in clinical settings.

[0021] A preferred embodiment of the present invention is to measure the expression levels of the transcription products (RNA) of two genes, the androgen receptor gene and the osteoglycin gene. In this case, the expression level of mRNA contained in prostate cancer tissue is analyzed, specifically, the RNA is converted into cDNA by reverse transcription, and then each cDNA or its amplification product is measured. For the extraction of RNA from prostate tissue, methods commonly used for the extraction or purification of RNA from biological samples, such as the phenol / chloroform method, the AGPC (acid guanidinium thiocyanate-phenol-chloroform extraction) method, or methods using columns such as TRIzol (registered trademark), RNeasy (registered trademark), and QIAzol (registered trademark), methods using special silica-coated magnetic particles, methods using Solid Phase Reversible Immobilization magnetic particles, and methods using columns such as ISOGEN and Pure Link. TM Extraction using commercially available RNA extraction reagents such as those listed above can be used.

[0022] For the reverse transcription, a primer targeting the specific RNA to be analyzed may be used, but for more comprehensive nucleic acid preservation and analysis, it is preferable to use a random primer. A general reverse transcriptase or reverse transcription reagent kit can be used for the reverse transcription. Preferably, a highly accurate and efficient reverse transcriptase or reverse transcription reagent kit is used, such as M-MLV Reverse Transcriptase and its variants, or a commercially available reverse transcriptase or reverse transcription reagent kit, such as the PrimeScript (registered trademark) Reverse Transcriptase series (Takara Bio Inc.) or the SuperScript (registered trademark) Reverse Transcriptase series (Thermo Scientific). Preferably used are SuperScript (registered trademark) III Reverse Transcriptase, SuperScript (registered trademark) VILO cDNA Synthesis kit (both manufactured by Thermo Scientific), etc. The temperature for the extension reaction in the reverse transcription is preferably adjusted to 42°C ± 1°C, more preferably 42°C ± 0.5°C, and even more preferably 42°C ± 0.25°C, while the reaction time is preferably adjusted to 60 minutes or longer, more preferably 80 to 120 minutes.

[0023] The RT-PCR may be either a commercially available one-step RT-PCR or a commercially available two-step RT-PCR. Furthermore, a commercially available quantitative RT-PCR may also be employed.

[0024] When measuring the expression level of a target gene using Northern blot hybridization, for example, probe DNA is first labeled with a radioisotope, a fluorescent substance, or the like, and then the resulting labeled DNA is hybridized with RNA derived from a biological sample that has been transferred to a nylon membrane or the like in a conventional manner. Thereafter, the formed double strand of labeled DNA and RNA is measured by detecting a signal derived from the label.

[0025] When measuring the expression level of a target gene using a DNA microarray, for example, an array having at least one nucleic acid (cDNA or DNA) derived from the target gene of the present invention immobilized on a support can be used, and labeled cDNA or cRNA prepared from mRNA can be bound to the microarray. The label on the microarray can then be detected to measure the expression level of mRNA. The nucleic acid immobilized on the array can be any nucleic acid that hybridizes specifically (i.e., substantially only to the nucleic acid of interest) under stringent conditions. For example, it can be a nucleic acid having the entire sequence of the target gene of the present invention, or a nucleic acid consisting of a partial sequence. Here, a "partial sequence" can be a nucleic acid consisting of at least 15 to 25 bases. Stringent conditions typically include washing conditions of approximately "1x SSC, 0.1% SDS, 37°C." More stringent hybridization conditions include approximately "0.5x SSC, 0.1% SDS, 42°C." Even more stringent hybridization conditions include approximately "0.1x SSC, 0.1% SDS, 65°C." Hybridization conditions are described in J. Sambrook et al., Molecular Cloning: A Laboratory Manual, Third Edition, Cold Spring Harbor Laboratory Press (2001), etc.

[0026] Thus, the expression levels of one or two genes selected from the androgen receptor gene and the osteoglycin gene or their transcription products in prostate tissue collected from a patient with metastatic hormone-sensitive prostate cancer are measured, and the prognosis of metastatic hormone-sensitive prostate cancer is predicted based on the expression levels. This prognosis prediction is preferably carried out, for example, by further comparing the measured expression levels with a reference value (cutoff value) for the gene or its transcription product to provide information for predicting the prognosis of metastatic hormone-sensitive prostate cancer. Furthermore, when analyzing the expression level of only the gene by RT-PCR or the like, a method in which the expression level of the target gene is converted to a relative expression level (relative quantification) based on the expression level of a housekeeping gene (e.g., GAPDH gene) as a reference standard is preferred, or a method in which the absolute copy number is quantified (absolute quantification) using a plasmid containing a region of the gene is preferred. The copy number may also be obtained by digital PCR.

[0027] "Prognosis" in the present invention includes all future outcomes of prostate cancer in a patient, but the present invention is particularly advantageous in that it can predict cancer-specific survival. Therefore, the "cutoff value" ("reference value") in the present invention is preferably a reference value that can predict cancer-specific survival. Such a reference value can be determined in advance, for example, based on the relationship between the J-CAPRA score of clinical data on metastatic hormone-sensitive prostate cancer that has been used conventionally and the expression level of the gene or its transcription product of the present invention. Specifically, the intersections of the points ranging from 0 to 100 in the upper row of Figure 1 with the numerical values ​​and points of an individual patient's J-CAPRA score, serum albumin level, serum LDH level, blood hemoglobin concentration, AR expression level, and osteoglycin expression level represent the respective points. Thus, the present invention is useful for diagnosing the prognosis of an individual patient, i.e., as a companion diagnosis. That is, if the J-CAPRA score is 7, it is 20 points, if the serum albumin value is 3.0, it is 0 points, if the serum LDH value is 221 or less, it is 60 points, if the blood hemoglobin concentration is 13.7 or more, it is 37.5 points, if the AR expression level is 0.7, it is 30 points, if the osteoglycin expression level is 0.3, it is 47.5 points, and the case will have a total of 195 points. If the total point is 195 points, the 1-year survival rate, 3-year survival rate, and 5-year survival rate in the lower row will be 90%, 60%, and 45%, and the cancer-specific survival rate due to prostate cancer can be estimated from the information at the time of diagnosis.

[0028] If the expression level of one or two genes (DNA) or their transcription products (RNA) selected from the androgen receptor gene and the osteoglycin gene is higher than the reference value, cancer-specific survival can be predicted.

[0029] Another aspect of the present invention is a prognosis prediction reagent for metastatic hormone-sensitive prostate cancer, comprising an oligonucleotide that specifically hybridizes with one or two genes selected from the androgen receptor gene and the osteoglycin gene, or their transcription products, or fragments thereof. Examples of the oligonucleotide that specifically hybridizes with the genes, their transcription products, or fragments thereof used in the reagent of the present invention include primer sets and probes used in PCR, with primer sets being more preferred. The nucleotide sequences of the androgen receptor gene and the osteoglycin gene are already known, and primer sets for amplifying these genes are also already known. In addition to the primer sets, the reagent may also contain a labeling reagent, a buffer solution, a chromogenic substrate, test equipment, control reagents used as positive and negative controls, a storage container, and the like.

[0030] The present invention is useful for companion diagnostics associated with prognosis prediction for metastatic hormone-sensitive prostate cancer. Companion diagnostics are clinical tests performed to predict the efficacy and side effects of pharmaceuticals before administration. By testing an individual patient's response to a drug before treatment, it is used to promote personalized medicine (or custom-made medicine). Applying the present invention to a hypothetical case, appropriate drug therapy can be selected at the time of diagnosis. That is, in a case with a serum PSA level of 500 ng / dL at diagnosis, a Gleason score of 4+4 in biopsy tissue, and cT3a N1 bone metastasis, the JCAPRA score is 2+3+2+1+3=11. If the serum albumin level is 3.5 g / dL, LDH is 220 IU / L, hemoglobin concentration is 10 g / dL, AR expression level is 0.5, and OGN expression level is 0.6, the total points are 100+10+60+0+40+30=240. Applying the nomogram of the present invention, the approximate 1-, 3-, and 5-year survival rates are 85%, 45%, and 28%, respectively. This is extremely poor when compared with the 66.7% 5-year survival rate of the prognostic curve from a previously reported multi-institutional study. Therefore, this hypothetical case would be a candidate for initial treatment with conventional androgen deprivation therapy, as well as new androgen preparations (abiraterone, XTANDI) or triple therapy (androgen deprivation therapy, an androgen preparation, and a taxane anticancer drug).

[0031] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[0032] Example 1 (Materials and Methods) This study used formalin-fixed, paraffin-embedded sections of primary tumors obtained from 103 treatment-naive male patients diagnosed with mHSPC by ultrasound-guided biopsy at Jichi Medical University Hospital between 2006 and 2018. The Jichi Medical University Hospital cohort was used for model testing. All patients underwent androgen deprivation therapy (ADT) via medical or surgical castration, and in some cases, antiandrogen therapy. After PSA relapse during initial ADT, further treatment was determined by the physician. Clinical data, including age, physical and laboratory data, and pathological records, were collected. Gleason score, PSA, and clinical TNM stage were converted to the Japan Cancer of the Prostate Risk Assessment (J-CAPRA) score, a validated risk assessment tool for predicting the outcome of ADT in prostate cancer patients. The J-CAPRA score is based on the biopsy Gleason score (3+3: 0 points, 3+4 and +4+3: 1 point, 8+: 2 points), PSA level (0-20 ng / mL: 0 points, 20-100 ng / mL: 1 point, 100-500 ng / mL: 2 points, ≥500 ng / mL: 3 points), clinical T stage (cT1a-cT2a: 0 points, cT2b-cT3a: 1 point, cT3b: 2 points, cT4: 3 points), clinical N stage (N0: 0 points, N1: 1 point), and clinical M stage (M0: 0 points, M1: 3 points).

[0033] Total RNA was isolated using the Pure Link FFPE Total RNA Isolation Kit (Thermo Fisher, Santa Clara, CA, USA). Excess paraffin, other than tissue, was removed from ten 10-μm-thick paraffin sections, and 300 μl of melting buffer was added. The mixture was then centrifuged for 10 seconds and incubated at 72°C for 10 minutes. Proteinase K (20 μl) was added, and the mixture was incubated at 60°C until the paraffin was completely dissolved. After centrifugation for 1 minute, the liquid was aspirated, and 400 μl of binding buffer and 800 μl of 100% ethanol were added. The tube was then bolted and centrifuged for 1 minute. The tube was then transferred to a collection tube with a cartridge and centrifuged at maximum speed for 2 minutes. The flow-through liquid was discarded, and this process was repeated twice. A mixture of wash buffer and ethanol (500 μL) was added, centrifuged at maximum speed for 1 minute, and the runoff was discarded. This procedure was repeated three times. The cartridge was transferred to a new tube, and 50 μL of RNA-free water preheated to 65°C was added. The mixture was then incubated at room temperature for 1 minute. RNA was extracted by centrifugation at maximum speed for 1 minute. Total RNA was treated with DNase I before cDNA synthesis. RNA quality and quantity were assessed using a nanodroplet spectrophotometer (Thermo Fisher, Santa Clara, CA, USA). Total RNA was converted to single-stranded cDNA using PrimeScript RT Master Mix (Takara). Quantitative reverse transcription PCR was performed using the StepOne system.

[0034] PCR conditions were as follows: an initial 20 seconds at 95°C, followed by 40 cycles of 1 second at 95°C and 20 seconds at 60°C.

[0035] The assay IDs used are as follows: Androgen receptor (AR): Hs00171172 Octameric transcription factor 1 (Oct1): Hs00427552 Kruppel-like factor 4 (Klf4): Hs0035836 Sulfatase 1 (SULF1): Hs00392834 Osteoglycin (OGN): Hs00247901 S100 calcium-binding protein A6 (S100A6): Hs00170953 Sex-determining region Y-box 2 (Sox2): Hs01053049 MYC proto-oncogene, bHLH transcription factor (Cmyc): Hs00153408 Ternary motif containing 36 (TRIM36): Hs01120401 Glyceraldehyde-3-phosphate dehydrogenase (GAPDH): Hs03929097 Estrogen receptor alpha (ERα): Hs01046816 The AR gene regulates prostate growth and is expressed at various stages of prostate cancer. Based on previous reports, the AR-related genes TRIM36 and Oct1 were also selected for this study. Stem cell-like markers Sox2, Klf4, and c-Myc were also evaluated. SULF1, a gene associated with prostate stromal cells, and S100A6, a prostate basal cell marker, were also evaluated. ERα, a prostate cancer-related gene primarily expressed in the prostate stroma, was also evaluated. OGN, which has been suggested in vitro to inhibit bone formation, was also evaluated.

[0036] Ethical approval for this study was obtained from the Jichi Medical University Institutional Review Board using the opt-out procedure (No. 21-002). Written informed consent was obtained from the patients to publish their details.

[0037] Statistics: Receiver operating characteristic (ROC) analysis was used to determine the best cutoff value for dichotomizing gene expression intensity to predict CSS. CSS was assessed using the Kaplan-Meier method and compared using the log-rank test. CSS was defined as the time interval from prostate cancer diagnosis to cancer-related death. Clinicopathological parameters and gene expression profiles were compared using univariate Cox proportional hazards analysis for CSS. Factors with a p-value <0.10 in univariate analysis were selected as candidates for subsequent multivariate analysis using the Cox hazard model for CSS. Based on the results of the multivariate analysis, a nomogram was constructed to predict the 1-, 3-, and 5-year probability of CSS in patients with mHSPC. The performance of our nomogram was evaluated using the concordance index (C-index). External validation of the newly established nomogram was performed using a validation cohort in which the gap between nomogram predictions and observed outcomes was assessed using the C-index.Statistical analyses were performed using EZR (Saitama Medical University, Jichi Medical University, Saitama, Japan), a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria).

[0038] (Results) The mean amount of total RNA obtained was 1916.0 ng (235.0-7880.0). The characteristics of mHSPC patients at the two institutions are shown in (Table 1). The median follow-up period was 36.9 months (range 3.3-153.1). The antiandrogens used in the Jichi Medical University Hospital cohort were bicalutamide in 79 cases (76.7%), chlormadinone acetate in 14 cases (13.6%), and eosin in 10 cases (9.7%). Potential predictors of CSS were evaluated in the model test cohort (n=103) (Table 2). Univariate analysis using the Cox proportional hazards model revealed that Gleason score, hemoglobin (≥13.7 g / dL or <13.7), serum albumin (≥3.1 g / dL or <3.1), serum lactate dehydrogenase (≥222 IU / L or none), total J-CAPRA score, AR expression level, and OGN expression level were associated with CSS (HR: 0.62, 0.40, 1.78, 1.17, 0.57, and 0.53, respectively; all p values ​​≤0.1). Of the six factors, Gleason score was excluded because it was included in the J-CAPRA score. A nomogram was constructed using the remaining five factors for 1-, 3-, and 5-year CSS (Figure 1). The C-index of the nomogram was 0.664. The background factors of the 103 mHSPC cases are listed in Table 1. Table 2 shows factors associated with cancer-specific survival (number of cases = 103) based on the Cox proportional hazards model.

[0039]

[0040]

[0041] The appropriate cutoff value for each gene was determined using a receiver operating characteristic curve (ROC) including OGN and AR. The cutoff values ​​for OGN and AR were 1.133 and 0.00, respectively. Patients were divided into two groups: OGN > 1.133 and OGN ≤ 1.133, AR > 0.00, and AR = 0.00. Kaplan-Meier curves for CSS are shown in Figure 2. Longer CSS was observed in the OGN > 1.133 (median CSS, 85.3 vs. 52.7 months, p = 0.082) and AR > 0.00 groups (median CSS, 69.1 vs. 32.1 months, p = 0.034). Analysis of the Human Protein Atlas dataset shows that in prostate cancer, the fragments per kilobase of exon per million reads (FPKM) for AR and OGN are 15.1 (5.1-33.7) and 6.4 (0.0-24.4), respectively.

[0042] Androgen receptor and osteoglycin are predictors of cancer-specific survival in hormone-sensitive prostate cancer, and a nomogram integrating them to predict CSS has been established.

Claims

1. A testing method for predicting the prognosis of metastatic hormone-sensitive prostate cancer, comprising the steps of measuring (a) the expression level of the osteoglycin gene or its transcription product, or (b) the expression levels of two genes, the androgen receptor gene and the osteoglycin gene, or their transcription products, in prostate tissue collected from a patient with metastatic hormone-sensitive prostate cancer.

2. The method for testing according to claim 1, comprising the step of measuring the expression levels of two genes, the androgen receptor gene and the osteoglycin gene, or their transcription products.

3. The method for testing according to claim 1 or 2, further comprising a step of comparing the measured expression level with a reference value for the gene or its transcription product to provide information for predicting the prognosis of metastatic hormone-sensitive prostate cancer.

4. The method according to any one of claims 1 to 3, wherein the expression level of the gene or its transcription product is the expression level of mRNA.

5. The method according to any one of claims 1 to 4, wherein the expression level of the gene or its transcription product is measured by PCR, Northern blot hybridization, or microarray.

6. The method according to any one of claims 1 to 5, wherein the expression level of the gene or its transcription product is measured by RT-PCR.

7. A companion diagnostic method based on the test according to any one of claims 1 to 6.

8. A prognosis prediction reagent for metastatic hormone-sensitive prostate cancer, comprising an oligonucleotide that specifically hybridizes with (a) the osteoglycin gene or its transcription product or a fragment thereof, or (b) two genes, the androgen receptor gene and the osteoglycin gene, or their transcription products or fragments thereof.

9. The reagent according to claim 8, comprising a primer set for amplifying (a) the osteoglycin gene or a transcription product thereof or a fragment thereof, or (b) two genes, i.e., the androgen receptor gene and the osteoglycin gene, or a transcription product thereof or a fragment thereof, or a probe that specifically hybridizes with (a) the osteoglycin gene or a transcription product thereof or a fragment thereof, or (b) two genes, i.e., the androgen receptor gene and the osteoglycin gene, or a transcription product thereof or a fragment thereof.

10. The reagent according to claim 8, comprising a primer set for amplifying (a) the osteoglycin gene, its transcription product, or a fragment thereof, or (b) two genes, the androgen receptor gene and the osteoglycin gene, or their transcription products, or fragments thereof.

11. The reagent according to any one of claims 8 to 10, wherein two genes, an androgen receptor gene and an osteoglycin gene, or transcription products thereof, or fragments thereof, are used.

12. A companion diagnostic agent comprising the prognosis prediction reagent according to any one of claims 8 to 11.