Neoadjuvant therapy for resectable and borderline resectable pancreatic cancer

[Stereotactic body radiotherapy for locally advanced pancreatic cancer: A systemic review]

Stereotactic body radiation therapy (SBRT) for locally advanced pancreatic cancer (LAPC) is an emerging treatment option. Most studies showed local control of approximately 75% with no evidence of improved overall survival. Gastrointestinal toxicities could be significant, ranging up to 22% for acute toxicities≥grade 3+ and 44% for late toxicities≥grade 3+. Currently, no standardized guidelines for treatment and management scheme. We conducted a systemic review of published prospective and retrospective trials to evaluate the efficacy, safety, technical data, and discuss future directions.

Neoadjuvant treatment strategies for resectable pancreas cancer: A propensity-matched analysis of the National Cancer Database

BACKGROUND AND PURPOSE

The optimal neoadjuvant approach in patients with resectable pancreas cancer is unclear. We investigated outcomes after preoperative chemotherapy alone, chemotherapy with conventionally-fractionated radiation (CFRT), or chemotherapy with stereotactic body radiotherapy (SBRT).

MATERIALS AND METHODS

The NCDB was queried for patients with resectable pancreatic adenocarcinoma (pretreatment stage T1-3, N0-1, M0) who received preoperative, multiagent chemotherapy and definitive surgery from 2010 to 2015. CFRT was 40-60 Gy in 20-35 fractions. SBRT was 20-25 Gy in 1 fraction or 30-50 Gy using at least 5 Gy per fraction. Multivariable regression and propensity score matching were used to adjust for potential confounders, including age, comorbidity score, and pretreatment extent of disease. The primary outcome was overall survival measured from surgery.

RESULTS

In total, 1355 patients received preoperative chemotherapy alone, 552 patients received preoperative chemotherapy with CFRT, and 175 patients received preoperative chemotherapy with SBRT. Receipt of SBRT was associated with significantly improved overall survival compared to chemotherapy alone (median 30 vs 21 months, p = 0.02; adjusted hazard ratio [HR] 0.65, 95% confidence interval [CI] 0.47-0.90, p = 0.01). Similarly, SBRT was associated with significantly improved overall survival compared to CFRT (median 29 vs 16 months, p = 0.002; adjusted HR 0.53, 95% CI 0.37-0.76, p = 0.001). Additionally, SBRT was associated with significantly increased rates of pathological complete response and margin-negative resection. Rates of postoperative readmissions and mortality were comparable.

CONCLUSIONS

Neoadjuvant chemotherapy with SBRT is associated with favorable survival and pathological outcomes, warranting consideration for prospective validation.

Histopathological effects of preoperative chemoradiotherapy for pancreatic cancer: an analysis for the impact of radiation and gemcitabine doses

BACKGROUND AND PURPOSE

Histopathological findings of patients who underwent resection for pancreatic adenocarcinoma (PC) after preoperative chemoradiotherapy (CRT) reportedly showed beneficial effects. The purpose of our study was to evaluate the correlation between histopathological effects (HE) of preoperative CRT and treatment parameters [radiation and gemcitabine (GEM) doses].

MATERIAL AND METHODS

HE of CRT were assessed on 158 primary lesions of 157 patients with PC who underwent pancreatic resection after preoperative CRT with GEM between January 2006 and December 2011. The radiation dose delivered to the primary tumor site and surrounding regional nodal areas was 50 Gy until September 2009 followed by the dose escalation of a 10 Gy boost added for delivery with the field-in-field technique to the roots of the celiac and superior mesenteric arteries. Intravenous administration of GEM (1000 /m(2)) was initiated concurrently on days 1, 8, and 15, every 4 weeks and generally repeated for 3 cycles. HE of CRT on the primary tumor were categorized based on the number of tumor cells destroyed.

RESULTS

The median overall survival time was 74.5 months and 3-year and 5-year survival rates were 64.3% and 54.5%, respectively. Dose-volume parameters of radiation such as D33 with a cut-off value of 51.6 Gy were correlated significantly with HE (p=.0230). Lesions having received GEM>7625 mg/m(2) before surgical resection more frequently showed positive HE (p=.0002). Multivariate logistic regression analysis demonstrated that both D33 and cumulative GEM dose were significant predictors of definite HE (p=.0110 and <.0001, respectively).

CONCLUSIONS

Our retrospective analysis showed that dose intensity of radiation and GEM is significantly related to HE of preoperative CRT for PC.

The role of radiation therapy in pancreatic ductal adenocarcinoma in the neoadjuvant and adjuvant settings

Pancreatic adenocarcinoma (PCA) is associated with high rates of cancer-related morbidity and mortality. Yet despite modern treatment advances, the only curative therapy remains surgical resection. The adjuvant therapeutic standard of care for PCA in the United States includes both chemotherapy and chemoradiation; however, an optimal regimen has not been established. For patients with resectable and borderline resectable PCA, recent investigation has focused efforts on evaluating the feasibility and efficacy of neoadjuvant therapy. Neoadjuvant therapy allows for early initiation of systemic therapy and identification of patients who harbor micrometastatic disease, thus sparing patients the potential morbidities associated with unnecessary radiation or surgery. This article critically reviews the data supporting or refuting the role of radiation therapy in the neoadjuvant and adjuvant settings of PCA management, with a particular focus on determining which patients may be more likely to benefit from radiation therapy.