Dose-painted intensity modulated radiation therapy improves local control for locally advanced pancreas cancer

Dose escalation of radiation therapy with or without induction chemotherapy for unresectable locally advanced pancreatic cancer

BACKGROUND

Dose escalation of conventionally fractionated radiation therapy (CFRT) above 45-54 Gy has an unclear survival benefit. Prior National Cancer Database (NCDB) analyses have shown improved overall survival with induction chemotherapy (iC) prior to concurrent chemoradiation (CRT) in locally advanced pancreatic cancer. Our study compared dose-escalated CFRT with and without iC.

METHODS

The NCDB was queried for primary stage III, cT4 N0-1 M0 LAPC treated with CRT with or without iC (2004-2015). CFRT was stratified by < 55 Gy and ≥ 55 Gy. Cohort iC + CRT and CRT included those with and without iC, respectively. The primary endpoint was overall survival (OS). Kaplan-Meier analysis, Cox proportional hazards method, and propensity score matching were used.

RESULTS

Among 2029 patients, cohort iC + CRT had 738 patients (n = 601 for 45-55 Gy and n = 137 for ≥55 Gy) and cohort CRT had 1291 patients (n = 1066 for 45-55 Gy and n = 225 for ≥55 Gy). Median follow-up was 24.3 months and 24.6 months for cohorts iC + CRT and CRT, respectively. Dose escalation showed improved survival in the multivariable analysis in cohort iC + CRT (HR 0.77, p = 0.013) but not in cohort CRT (HR 0.91, p = 0.19). Using 2:1 propensity score matching, a total of 387 patients for cohort iC + CRT and 549 patients for cohort CRT were matched. After matching, dose escalation remained significant for improved overall survival in cohort iC + CRT (median OS 16.2 vs 15.2 months; 2-yr OS 33.4% vs 25.4%; p = 0.022) but not in cohort CRT (median OS 11.8 vs 10.6 months; 2-yr OS 13.3% vs 10.1%; p = 0.16).

CONCLUSIONS

Patients with locally advanced pancreatic cancer who undergo iC have improved survival with radiation dose escalation above 55 Gy. For patients without iC, there is no clear association between radiation dose escalation and survival.

Chemotherapy and intensity-modulated radiation therapy for locally advanced pancreatic cancer achieves a high rate of R0 resection

BACKGROUND

To assess local control, survival and conversion to resectability among locally advanced pancreatic cancer (LAPC) patients treated with induction chemotherapy (ICT) followed by chemoradiotherapy treatment using intensity-modulated radiation therapy (IMRT).

MATERIAL AND METHODS

Between 2007 and 2012, 134 LAPC patients were treated with ICT followed by IMRT. After chemoradiotherapy, 40 patients received maintenance chemotherapy.

RESULTS

With a median follow-up of 20 months, median overall survival (OS) was 23 months. One- and two-year OS was 85% and 47%, respectively. On multivariate analysis, progression of disease after IMRT was associated with worse OS. Cumulative incidence of local failure was 10% at one year and 36% at two years. Twenty-six patients (19%) underwent resection after chemoradiotherapy including 22 patients (85%) with negative margins. On multivariate analysis, response to IMRT was associated with surgery (p = .01). Acute grade 3-4 hematologic and non-hematologic toxicity rates were 26% and 4.5%, respectively.

CONCLUSION

IMRT is safe in patients with LAPC. Patients with non-progressive LAPC after ICT and who received IMRT had high rates of local control and prolonged survival.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.