Docetaxel, Oxaliplatin, and 5-Fluorouracil (DOF) in Metastatic and Unresectable Gastric/Gastroesophageal Junction Adenocarcinoma: A Phase II Study with Long-Term Follow-Up.

LESSONS LEARNED: Adding docetaxel to the modified FOLFOX7 backbone (DOF) is a feasible three-drug combination therapy for advanced gastric cancer with high activity, providing evidence that leucovorin is not necessary in this setting.The DOF regimen represents an alternative to the FLOT (5-FU 2,600 mg/m2 as 24-hour infusion with leucovorin 200 mg/m2, oxaliplatin 85 mg/m2, and docetaxel 50 mg/m2) regimen that can be considered in select patients with advanced gastric cancer and is a potential choice in the curative setting. BACKGROUND: The combination of docetaxel, cisplatin, and 5-fluorouracil (5-FU) demonstrates high response rates in advanced gastric cancer, albeit with increased toxicity. Given the efficacy of platinum-taxane-fluoropyrimidine regimens, this phase II study evaluated the efficacy and toxicity of docetaxel, oxaliplatin, and 5-FU (DOF) for the treatment of metastatic or unresectable gastric or gastroesophageal junction (GEJ) adenocarcinoma. METHODS: Patients with metastatic or unresectable gastric or GEJ adenocarcinoma with no prior therapy for metastatic disease received docetaxel 50 mg/m2 on day 1, oxaliplatin 85 mg/m2 on day 1, and 5-FU 2,400 mg/m2 continuous intravenous infusion over 46 hours; cycles were repeated every 2 weeks. The primary endpoint was overall response rate (ORR). RESULTS: Forty-four patients were enrolled. Assessment of treatment response and toxicity was feasible in 41 and 43 patients, respectively. ORR was 73.2% (68.3% partial response; 4.9% complete response). Therapy was discontinued for progressive disease in 53%, toxicity in 26%, and death on treatment in 16%. Two patients underwent surgical resection. Thirty-three patients (76.7%) received at least seven cycles (7-34). Grade 3-4 toxicities occurred in 31 patients (72.1%), including neutropenia (23.3%), neurologic (20.9%), and diarrhea (14.0%). Median overall survival was 10.3 months. CONCLUSION: DOF demonstrates a high response rate, expected safety profile, and prolonged survival and remains an option for select patients with unresectable or metastatic gastric or GEJ adenocarcinoma.

Somatic acquisition and signaling of TGFBR1*6A in cancer.

CONTEXT: TGFBR1*6A is a common polymorphism of the type I transforming growth factor beta receptor (TGFBR1). Epidemiological studies suggest that TGFBR1*6A may act as a tumor susceptibility allele. How TGFBR1*6A contributes to cancer development is largely unknown. OBJECTIVES: To determine whether TGFBR1*6A is somatically acquired by primary tumors and metastases during cancer development and whether the 3-amino acid deletion that differentiates TGFBR1*6A from TGFBR1 is part of the mature receptor or part of the signal sequence and to investigate TGFBR1*6A signaling in cancer cells. DESIGN, SETTING, AND PATIENTS: Tumor and germline tissues from 531 patients with a diagnosis of head and neck, colorectal, or breast cancer recruited from 3 centers in the United States and from 1 center in Spain from June 1, 1994, through June 30, 2004. In vitro translation assays, MCF-7 breast cancer cells stably transfected with TGFBR1*6A, TGFBR1, or the vector alone, DLD-1 colorectal cancer cells that endogenously carry TGFBR1*6A, and SW48 colorectal cancer cells that do not carry TGFBR1*6A. MAIN OUTCOME MEASURES: TGFBR1*6A somatic acquisition in cancer. Determination of the amino terminus of the mature TGFBR1*6A and TGFBR1 receptors. Determination of TGF-beta-dependent cell proliferation. RESULTS: TGFBR1*6A was somatically acquired in 13 of 44 (29.5%) colorectal cancer metastases, in 4 of 157 (2.5%) of colorectal tumors, in 4 of 226 (1.8%) head and neck primary tumors, and in none of the 104 patients with breast cancer. TGFBR1*6A somatic acquisition is not associated with loss of heterozygosity, microsatellite instability, or a mutator phenotype. The signal sequences of TGFBR1 and TGFBR1*6A are cleaved at the same site resulting in identical mature receptors. TGFBR1*6A may switch TGF-beta growth inhibitory signals into growth stimulatory signals in MCF-7 breast cancer cells and in DLD-1 colorectal cancer cells. CONCLUSIONS: TGFBR1*6A is somatically acquired in 29.5% of liver metastases from colorectal cancer and may bestow cancer cells with a growth advantage in the presence of TGF-beta. The functional consequences of this conversion appear to be mediated by the TGFBR1*6A signal sequence rather than by the mature receptor. The results highlight a new facet of TGF-beta signaling in cancer and suggest that TGFBR1*6A may represent a potential therapeutic target in cancer.

Combined genetic assessment of transforming growth factor-beta signaling pathway variants may predict breast cancer risk.

There is growing evidence that common variants of the transforming growth factor-beta (TGF-beta) signaling pathway may modify breast cancer risk. In vitro studies have shown that some variants increase TGF-beta signaling, whereas others have an opposite effect. We tested the hypothesis that a combined genetic assessment of two well-characterized variants may predict breast cancer risk. Consecutive patients (n = 660) with breast cancer from the Memorial Sloan-Kettering Cancer Center (New York, NY) and healthy females (n = 880) from New York City were genotyped for the hypomorphic TGFBR1*6A allele and for the TGFB1 T29C variant that results in increased TGF-beta circulating levels. Cases and controls were of similar ethnicity and geographic location. Thirty percent of cases were identified as high or low TGF-beta signalers based on TGFB1 and TGFBR1 genotypes. There was a significantly higher proportion of high signalers (TGFBR1/TGFBR1 and TGFB1*CC) among controls (21.6%) than cases (15.7%; P = 0.003). The odds ratio [OR; 95% confidence interval (95% CI)] for individuals with the lowest expected TGF-beta signaling level (TGFB1*TT or TGFB1*TC and TGFBR1*6A) was 1.69 (1.08-2.66) when compared with individuals with the highest expected TGF-signaling levels. Breast cancer risk incurred by low signalers was most pronounced among women after age 50 years (OR, 2.05; 95% CI, 1.01-4.16). TGFBR1*6A was associated with a significantly increased risk for breast cancer (OR, 1.46; 95% CI, 1.04-2.06), but the TGFB1*CC genotype was not associated with any appreciable risk (OR, 0.89; 95% CI, 0.63-1.21). TGFBR1*6A effect was most pronounced among women diagnosed after age 50 years (OR, 2.20; 95% CI, 1.25-3.87). This is the first study assessing the TGF-beta signaling pathway through two common and functionally relevant TGFBR1 and TGFB1 variants. This approach may predict breast cancer risk in a large subset of the population.

No major association between TGFBR1*6A and prostate cancer.

Prostate cancer is the most commonly diagnosed cancer in men and one of the leading causes of cancer deaths. There is strong genetic evidence indicating that a large proportion of prostate cancers are caused by heritable factors but the search for prostate cancer susceptibility genes has thus far remained elusive. TGFBR1*6A, a common hypomorphic variant of the type I Transforming Growth Factor Beta receptor, is emerging as a tumor susceptibility allele that predisposes to the development of breast, colon and ovarian cancer. The association with prostate cancer has not yet been explored. A total of 907 cases and controls from New York City were genotyped to test the hypothesis that TGFBR1*6A may contribute to the development of prostate cancer. TGFBR1*6A allelic frequency among cases (0.086) was slightly higher than among controls (0.080) but the differences in TGFBR1*6A genotype distribution between cases and controls did not reach statistical significance (p = 0.67). Our data suggest that TGFBR1*6A does not contribute to the development of prostate cancer.