Abstract P5-23-01: Clinical and biological characterization of male breast cancer (BC) EORTC 10085/TBCRC 029/BOOG 2013-02/BIG 2-07: Baseline results from the prospective registry

BACKGROUND: Through the International Male Breast Cancer Program, a prospective registry for male BC was created with the goals of evaluating 1) the clinical and biological features of this disease and 2) assessing feasibility of a prospective therapeutic clinical trial.

METHODS: All men, with any stage histologically proven invasive breast cancer, age 3 18 years, and newly presenting at the participating institutions (within 3 months prior) were eligible. Patients were enrolled for 30 months after activation of the first center, through February 2017. Per the study design, if <100 men enrolled, the study would be considered a failure and therapeutic trials would not be pursued through this network. Epidemiologic data, staging, pathologic features, and BRCA status were collected. Treatment and outcome data collection is ongoing. Optional collection of FFPE tumor samples, blood, and QOL were performed in the US, the Netherlands, and Latin America. Clinical database lock for this report was May 30, 2017. We currently report patient and disease characteristics and will update with patterns of treatment for the presentation. Outcomes and biological samples will be analyzed in the future.

RESULTS: 557 patients were enrolled: 75% in Europe, 20% in United States, 5% in other countries. 6.3% of patients had missing forms. Median age was 67 years (range 26-92). 93% were diagnosed 2010-2017. Among patients with complete data, 79% presented with a breast mass. 88% were M0 and 12% M1. Among M0 patients: 47%, 39%, 2%, and 11% had T1, T2, T3, and T4 disease respectively; 52% were N0. Overall, 98% had ER+ disease and 11% had HER2+ cancer. 14% had grade 1, 56% had grade 2, and 30% had grade 3 tumors. Among 112 men who underwent BRCA1 testing, 1 was positive. Among 118 men who had BRCA2 testing, 18 (15%) were positive. 21% of men had prior or concurrent malignancies, with the following most common sites: prostate, non-melanoma skin, colorectal, and melanoma. The prevalence of previously identified possible risk factors for male breast cancer were: overweight/obesity (72%), former/current smoker (51%), current alcohol 31 drink daily (41%), family history of breast cancer (35%), gynecomastia (16%), history radiation exposure (8%), use of anti-androgens (1%), and use of estrogens (1%).

CONCLUSION: Through an international collaborative effort, we were able to prospectively accrue 557 patients to a male breast cancer registry. These results demonstrate feasibility of pursuing a therapeutic clinical trial in men with breast cancer. In addition, this study shows the relatively low uptake of BRCA testing, high rates of concurrent/prior malignancy, and the rates of potentially modifiable risk factors in this patient population.

Funding from Breast Cancer Research Foundation, Susan G. Komen, Dutch Pink Ribbon Foundation, Swedish Breast Cancer Association (BRO) and EBCC Council.

Citation Format: Giordano SH, Schröder CP, Poncet C, van Leeuwen-Stok E, Linderholm B, Abreu MH, Rubio I, Van Poznak C, Morganstern D, Cameron D, Vleugel MM, Smilde TJ, Bozovic-Spasojevic I, Korde L, Russell NS, den Hoed IDM, Honkoop AH, van der Velden AWG, van 't Riet M, Dijkstra N, Bogler O, Goulioti T, Hilsenbeck S, Ruddy KJ, Wolff A, van Deurzen CHM, Martens J, Bartlett JMS, Aalders K, Tryfonidis K, Cardoso F. Clinical and biological characterization of male breast cancer (BC) EORTC 10085/TBCRC 029/BOOG 2013-02/BIG 2-07: Baseline results from the prospective registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-23-01.

A phase I study of EC145 administered weeks 1 and 3 of a 4-week cycle in patients with refractory solid tumors

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Background: Folic acid is internalized via two main pathways; a reduced folate carrier (RFC) or a folate-specific receptor (FR). While FR is minimally distributed in normal tissues, it is over-expressed in many human tumors, including cancers of the ovary, lung and kidney. Experimental data indicate that EC145, a conjugate of folic acid and the vinca alkaloid desacetylvinblastine hydrazide (DAVLBH), is a high-affinity ligand for the folate receptor (FR) but not for RFC. EC145 is also highly active against FR-positive KB tumors in vivo. This phase I trial assessed the safety and pharmacokinetics (PK) of escalating bolus doses of EC145. Methods: The phase I study treated eligible patients with EC145 as an intravenous bolus according to a ‘flat dose‘ escalation plan on days 1, 3, 5 (week 1) and 15, 17, 19 (week 3) of a 4-week cycle. Endpoints included determination of a safe and tolerable EC145 dose, development of a PK model, and identification of antitumor activity. Results: As of Dec 2006, 16 patients had received bolus EC145 (1.2, 2.5 or 4 mg; n = 3, 11 and 2, respectively). EC145 was generally well tolerated at bolus doses < 2.5 mg with one patient continuing on study for 6 cycles. Overall, the most common side effects were fatigue (n = 9), constipation (n = 7) and neuropathy (n = 6). DLT at 4 mg included reversible ileus and neuropathy. Formal PK analysis will be available at the time of presentation. One patient has had a minor response and another has exhibited disease stabilization > 5 months (both ovarian cancer patients). Upon declaration of the bolus MTD, the trial was amended to explore the utility of a 1-hour EC145 infusion to take full advantage of potential high affinity interaction between EC145 and the FR to effect drug targeting. As of Jan 2, 2007, three patients had been accrued to a dose level of 2.5 mg over 1 hr, and all tolerated the therapy without significant toxicity. Conclusions: EC145 may be administered safely as a 2.5 mg intravenous bolus dose on days 1, 3, 5 (week 1) and 15, 17, 19 (week 3) of a 28-day schedule.

No significant financial relationships to disclose.

Chemo-hormonal therapy for biochemical progression of prostate cancer

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Background: Androgen deprivation therapy (ADT) is effective for relapsed prostate cancer, but is rarely curative. The purpose of this trial was to determine the feasibility, toxicity and PSA response of chemotherapy and ADT for men with PSA relapse. Methods: Eligible men had a rising PSA and no metastases after prostatectomy and/or radiation for localized disease. Treatment consisted of four cycles of docetaxel (70 mg/M2) every 21 days and estramustine 280 mg three times daily on days 1–5. After chemotherapy, goserelin acetate and bicalutamide 50 mg daily were prescribed for 15 months. Results: Sixty-two patients were enrolled at four institutions: median age 65 (range 49–78), median PSA 3.01 ng/mL (range 0.08–47.04), 24% Gleason 8–10. A complete PSA response (CR) was defined as PSA at or below assay-specific lower limit (0.01–0.2 ng/mL). The proportion of patients with CR after chemotherapy, after ADT and at one year off ADT was 53%, 63% and 36%. Testosterone was > 100 ng/dL (median 250 ng/dL) one year off ADT in 97%. Patients with a PSA < 3.0 ng/mL had a significantly longer time to progression (p-value 0.0002). At the time of last follow-up 24/56 (43%) who are at least one year off ADT have not progressed. Median TTP is 34 months from treatment initiation (maximum 74 months free from progression). Toxicity was manageable with no toxic deaths: there were 4 thromboses on chemotherapy and 38% of cycles were associated with grade III/IV neutropenia with 5 cases of documented infections. Conclusion: Chemotherapy prior to hormone therapy was feasible for early prostate cancer relapse. Forty-three percent of men who are at least one year off ADT with recovered testosterone have not progressed. This approach is being tested in a randomized trial with investigation of predictors of response.

No significant financial relationships to disclose.

Tyrosine kinases expressed in vivo by human prostate cancer bone marrow metastases and loss of the type 1 insulin-like growth factor receptor

An important biological feature of prostate cancer (PCa) is its marked preference for bone marrow as a metastatic site. To identify factors that may support the growth of PCa in bone marrow, expression of receptor and nonreceptor tyrosine kinases by androgen-independent PCa bone marrow metastases was assessed. Bone marrow biopsies largely replaced by PCa were analyzed using reverse transcriptase-polymerase chain reaction amplification with degenerate primers that amplified the conserved kinase domain. Sequence analyses of the cloned products demonstrated expression of multiple kinases. Expression of the receptor and nonreceptor tyrosine kinases, alpha platelet-derived growth factor receptor and Jak 1, respectively, was confirmed by immunohistochemistry. In contrast, the type 1 insulin-like growth factor receptor, thought to play a role in PCa development, was lost in metastatic PCa. These results implicate several specific growth factors and signaling pathways in metastatic androgen-independent PCa and indicate that loss of the type 1 insulin-like growth factor receptor contributes to PCa progression.

Genitourinary cancers in older adults

Prostate and bladder carcinoma are, in large part, diseases of older adults, and they are discussed in this context. Pathology, diagnosis, and staging are reviewed. Surgical and medical approaches to these malignancies, and the limitations of these approaches, are highlighted. Renal cell carcinoma, while a relatively rare neoplasm, remains a formidable challenge: approximately 50% of patients die within 5 years of diagnosis. Advances in molecular genetics and histopathologic classification, as well as surgical management and investigational therapies, are emphasized.