Tchelebi, Leila T.

Objectives: Deaths from an unknown cause are difficult to adjudicate and oncologic studies of comparative effectiveness often demonstrate inconsistencies in incorporating these deaths and competing events (eg, heart disease and stroke) in their analyses. In this study, we identify cancer patients most at risk for death of an unknown cause. Methods: This retrospective, population-based study used cancer registry data from the Surveillance, Epidemiology, and End Results database (1992-2015). The absolute rate of unknown causes of death (COD) cases stratified by sex, marital status, race, treatment, and cancer site were calculated and a multivariable logistic regression model was applied to obtain adjusted odds ratios with 95% CIs. Results: Out of 7,154,779 cancer patients across 22 cancer subtypes extracted from Surveillance, Epidemiology, and End Results, 3,448,927 died during follow-up and 276,068 (7.4%) of these deaths were from unknown causes. Patients with an unknown COD had a shorter mean survival time compared with patients with known COD (36.3 vs 65.7 mo, P < 0.001). The contribution of unknown COD to total mortality was highest in patients with more indolent cancers (eg, prostate [12.7%], thyroid [12.3%], breast [10.7%]) and longer follow-up (eg, >5 to 10 y). One, 3, and 5-year cancer-specific survival (CSS) calculations including unknown COD were significantly decreased compared with CSS estimates excluding cancer patients with unknown COD. Conclusion: Of the patients, 7.4% died of unknown causes during follow-up and the proportion of death was higher with longer follow-up and among more indolent cancers. The attribution of high percentages of unknown COD to cancer or non-cancer causes could impact population-based cancer registry studies or clinical trial outcomes with respect to measures involving CSS and mortality.

Although uncommon, extrahepatic cholangiocarcinoma (EHCC) is a deadly malignancy, and the treatment approaches remain controversial. While surgery remains the only cure, few patients are candidates for resection up front, and there are high rates of both local and distant failure following resection. Herein, we systematically review the available evidence regarding treatment approaches for patients with EHCC, including surgery, radiation, and chemotherapy. The evidence regarding treatment outcomes was assessed using the Population, Intervention, Comparator, Outcome, and Study design (PICOS) framework. A summary of recommendations based on the available literature is outlined for specific clinical scenarios encountered by providers in the clinic to guide the management of these patients.

Background: Increased facility surgical treatment volume is sometimes associated with improved survival in patients with cancer; however, published studies evaluating volume are heterogeneous and disparate in their patient inclusion and definition of volume. The purpose of this work was to evaluate uniformly the impact of surgical facility volume on survival in patients with cancer. Methods: The National Cancer Database was searched for patients diagnosed in 2004 through 2013 with the 12 cancers most commonly treated surgically. Facilities were stratified by 4 categories using the overall population (low, intermediate, high, and very high), each including 25% of patients, and then stratified by each individual disease site. Five-year postsurgery survival was estimated using both the Kaplan-Meier method and corresponding log-rank tests for group comparisons. Cox proportional hazard models were used to evaluate the effects of facility volume on 5-year postsurgery survival further, adjusted for multiple covariates. Results: A total of 3,923,618 patients who underwent surgery were included from 1,139 facilities. Of these, 40.4% had breast cancer, 12.8% prostate cancer, and 10.0% colon cancer. Most patients were female (65.0%), White (86.4%), and privately insured (51.6%) with stage 0–III disease (64.8%). For all cancers, the risk of death for patients undergoing surgery at very high-volume facilities was 88% of that for those treated at low-volume facilities. Hazard ratios (HRs) were greatest (very high vs low volume) for cancer of the prostate (HR, 0.66; 95% CI, 0.63–0.69), pancreas (HR, 0.75; 95% CI, 0.71–0.78), and esophagus (HR, 0.78; 95% CI, 0.73–0.83), and for melanoma (HR, 0.81; 95% CI, 0.78–0.84); differences were smallest for uterine and non–small cell lung cancers. Overall survival differences were greatest for cancers of the brain, pancreas, and esophagus. Conclusions: Patients treated surgically at higher-volume facilities consistently had improved overall survival compared with those treated at low-volume centers, although the magnitude of difference was cancer-specific.

Abstract Background We hypothesized that the addition of receptor tyrosine kinase inhibitors (RTKis, e.g., lapatinib, erlotinib, cetuximab, bevacizumab, panitumumab) to radiotherapy-based treatment for solid tumors does not increase overall survival but may increase toxicity. Methods Population, Intervention, Control, Outcome, Study Design; Preferred Reporting Items for Systematic Reviews and Meta-Analyses; and Meta-analysis of Observational Studies in Epidemiology methods were used to identify prospective randomized studies including patients with solid tumor cancers treated with radiotherapy with or without RTKis. Extracted variables included use of radiotherapy vs chemoradiotherapy, RTKi type (antibody vs small molecule), outcomes, and toxicities. The primary endpoint was overall survival; the secondary endpoint was grade 3+ toxicity. Random-effects meta-analyses were performed for each outcome measure. All statistical tests were 2-sided. Results A total of 405 studies met the initial search criteria, of which 13 prospective randomized trials of radiotherapy with or without RTKi met the inclusion criteria, encompassing 5678 patients. The trials included cancers of the head and neck (6 trials, 3295 patients), esophagus (3 trials, 762 patients), lung (2 trials, 550 patients), and brain (2 trials, 1542 patients). Three studies evaluated a small molecule and radiotherapy in 949 patients, and 10 studies evaluated antibodies and radiotherapy in 4729 patients. The addition of RTKis to radiotherapy-based treatment did not improve overall survival (hazard ratio = 1.02, 95% confidence interval = 0.90 to 1.15, P = .76) but increased grade 3+ toxicity (relative risk = 1.18, 95% confidence interval = 1.06 to 1.33, P = .009). Conclusions The addition of RTKis to radiotherapy does not improve survival and worsens toxicity.

Background The goal of this study was to characterize the efficacy and safety of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy with concurrent chemotherapy (CFRT) for the definitive treatment of locally advanced pancreatic cancer. The primary outcome measure was efficacy, defined by 2‐year overall survival (OS). Secondary outcomes were incidence of any grade 3/4 toxicity and 1‐year OS. Methods A PICOS/PRISMA/MOOSE selection protocol was used to identify eligible studies. Inclusion criteria were: 1) patients diagnosed with locally advanced N0‐1 M0 pancreatic cancer; 2) CFRT 1.8 to 2.0 Gy/fraction with chemotherapy per protocol or SBRT ≥5 Gy/fraction in ≤5 fractions; 3) either no control group or another definitive chemotherapy or radiation therapy arm; 4) at least 1 of the outcome measures reported; and 5) single or multi‐arm phase 2/3 prospective study for CFRT and/or phase 1/2 or retrospective study for SBRT. Neoadjuvant and/or adjuvant chemotherapy was prescribed per protocol specifications. Weighted random effects meta‐analyses were conducted using the DerSimonian and Laird method to characterize summary effect sizes for each outcome. Results A total of 470 studies were initially screened; of these, 9 studies assessed SBRT and 11 studies assessed CFRT. For SBRT, the median dose was 30 Gy, and the most common regimen was 30 Gy/5 fractions. For CFRT, doses ranged from 45 to 54 Gy in 1.8‐ to 2.0‐Gy fractions, with the majority of studies delivering 50.4 Gy in 28 fractions with concurrent gemcitabine. The random effects estimate for 2‐year OS was 26.9% (95% CI, 20.6%‐33.6%) for SBRT versus 13.7% (95% CI, 8.9%‐19.3%) for CFRT and was statistically significant in favor of SBRT. The random effects estimate for 1‐year OS was 53.7% (95% CI, 39.3%‐67.9%) for SBRT versus 49.3% (95% CI, 39.3%‐59.4%) for CFRT, and was not statistically significant. The random effects estimate for acute grade 3/4 toxicity was 5.6% (95% CI, 0.0%‐20.0%) for SBRT versus 37.7% (95% CI, 24.0%‐52.5%) for CFRT and was statistically significant in favor of SBRT. The random effects estimate for late grade 3/4 toxicity was 9.0% for SBRT (95% CI, 3.3%‐17.1%) versus 10.1% (95% CI, 1.8%‐23.8%) for CFRT, which was not statistically significant. Conclusion These results suggest that SBRT for LAPC may result in a modest improvement in 2‐year OS with decreased rates of acute grade 3/4 toxicity and no change in 1‐year‐OS or late toxicity. Further study into the use of stereotactic body radiation therapy for these patients is needed.