While previous studies showed that patients (pts) with PC and long-standing DM had worse survival than pts without DM, the impact of the duration of DM on therapeutic outcomes has not been sufficiently studied in pts receiving chemotherapy for mPC.
We retrospectively analyzed the therapeutic results for pts with mPC who received G as standard therapy before the introduction of combination regimens at two sites of the National Cancer Center (“Tokyo” and “Kashiwa”). The efficacies and toxicities of G were compared among three groups classified by the DM duration: no DM, short-term DM (< 4 years), and long-term DM (≥ 4 years). To examine the associations of the DM duration with overall survival (OS) and progression free survival (PFS), Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for the baseline characteristics.
Overall, 350 pts (“Tokyo”: n = 202, 2008-2013; “Kashiwa”: n = 148, 2008-2011), were included: 218, 87, and 45 in the no DM, short-term DM, and long-term DM groups, respectively. No statistically significant differences in baseline characteristics were observed among the three groups except for BMI (median [kg/m2]: 20.7, 21.4, and 22.5; p = 0.015, Kruskal–Wallis test). Compared with the no DM group, multivariable-adjusted HRs for PFS were 1.33 (95% CI, 0.94-1.89; p = 0.103) for the long-term DM group and 1.12 (95% CI, 0.85-1.47; p = 0.410) for the short-term DM group; and those for OS were 1.37 (95% CI, 0.95-1.98; p = 0.096) and 1.10 (95% CI, 0.82-1.46; p = 0.533), respectively. There were no substantial differences in HRs between “Tokyo” and “Kashiwa” (e.g., HRs of long-term DM for PFS were 1.54 [95% CI, 0.98-2.44] and 1.33 [95% CI, 0.80-2.21], respectively; HRs of long-term DM for OS were 1.32 [95% CI, 0.82-2.14] and 1.34 [95% CI, 0.80-2.26], respectively). Also, HRs for PFS and OS did not substantially change with different cutoff years of DM duration (ranges of HRs of long-term DM with cutoff at 3-5 years: PFS, 1.36-1.55; OS, 1.21-1.33). No significant differences in tumor response and toxicity were observed.
A long pretreatment history of DM may be associated with a shorter PFS and OS among pts with mPC.
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National Cancer Center Hospital
M. Ikeda: Advisory board membership of Nano Carrier; research funding from Yakult, Taiho, Ono, Eisai, AstraZeneca, Zeria, Merck Serono, Baxter, and Nano Carrier; honoraria from Novartis, Taiho, Chugai, Daiichi Sankyo, Eli Lilly, and Yakult. S. Kondo: Research funding from Pfizer, Merck Serono, AstraZeneca, Bayer, and Eli Lilly. C. Morizane: Honoraria from Pfizer, Novartis, Yakult, Eli Lilly, and Nobelpharma; advisory role in AstraZeneca, Yakult, Novartis, and Taiho; an Immediate Family Member received honoraria from FUJIFILM RI Pharma. S. Mitsunaga: Honoraria from Ono and Toray; research funding from Bayer, Chugai, Merck Serono, ASLAN, and Ajinomoto. All other authors have declared no conflicts of interest.