Vivek Verma, Swati M. Surkar, Eric D. Brooks, Charles B. Simone II and Chi Lin
Purpose: Current guidelines recommend chemotherapy (CT) with or without radiotherapy for unresected nonmetastatic gallbladder cancer (GC), with little consensus. However, several small-volume, single-institution studies have documented the efficacy of local therapy for this population. This is the largest study to date evaluating outcomes of chemoradiotherapy (CRT) versus CT alone in unresected nonmetastatic GC. Methods: The National Cancer Database was queried for primary GC cases (2004–2013) receiving CT alone or CRT. Patients receiving resection or lack of CT were excluded, as were those with metastatic disease or unknown M classification. Logistic regression analysis ascertained factors associated with CRT delivery. Kaplan-Meier analysis evaluated overall survival (OS) between both cohorts. Cox proportional hazards modeling determined variables associated with OS. Results: In total, 1,199 patients were analyzed (CRT: n=327, 27%; CT: n=872, 73%). Groups were evenly balanced, with no factor on multivariate logistic regression analysis statistically predicting for receipt of a particular paradigm. Median OS in the CRT and CT groups was 12.9 versus 7.8 months, respectively (P=.001). On multivariate analysis, OS was associated with age and years of treatment (P=.001 each). Notably, receipt of CRT independently predicted for improved OS (P=.001). Conclusions: CRT, compared with CT alone, was independently associated with improved survival in unresected nonmetastatic GC. Although causation is not implied, these results support the necessity for prospective CRT evaluation.
Vivek Verma, Pamela K. Allen, Charles B. Simone II, Hiram A. Gay and Steven H. Lin
Background: Management of metastatic (M1) nasopharyngeal cancer (NPC) is controversial; data suggest high overall survival (OS) rates with definitive chemoradiotherapy (CRT). Herein, we evaluated OS in patients with M1 NPC undergoing chemotherapy alone versus CRT. Methods: The National Cancer Data Base was queried for M1 NPC cases. Patients undergoing no/unknown chemotherapy and/or with unknown/nondefinitive radiotherapy (RT) doses (<60 Gy) were excluded. Logistic regression analysis ascertained clinical factors associated with RT administration. Kaplan-Meier analysis evaluated OS between both cohorts; Cox proportional hazards modeling assessed factors associated with OS. Survival was then evaluated between matched populations using inverse-probability–weighted regression adjustment. OS between groups was also measured in patients surviving ≥1 and ≥3 years to address bias from poor-prognostic subsets (eg, widely disseminated disease), and those receiving CRT ≤30 and ≤60 days of each other (surrogates for concurrent CRT) versus >30 and >60 days (sequential) of each other. Results: Of 555 patients, 296 (53%) received chemotherapy alone and 259 (47%) underwent CRT. Patients undergoing CRT more often had private insurance (P=.001) and lived in areas with higher education levels (P=.028). Median OS in the chemotherapy-only and CRT cohorts were 13.7 and 25.8 months, respectively (P<.001); differences persisted between matched populations (P<.001). On multivariate analysis, receipt of additional RT independently predicted for improved OS (P<.001). OS differences between cohorts remained apparent when evaluating patients surviving for ≥1 (P<.001) and ≥3 (P=.002) years. Patients who received concurrent or sequential CRT displayed improved OS over those receiving chemotherapy alone, for both the 30-day (P<.001) and 60-day cutoffs (P<.001). Conclusions: Patients with M1 NPC undergoing definitive RT and chemotherapy experienced higher survival than those receiving chemotherapy alone. Risk stratification and patient selection for such combined modality interventions is critical.
Vivek Verma, Amy C. Moreno, Waqar Haque, Penny Fang and Steven H. Lin
Background: Postoperative chemoradiotherapy (CRT) for non–small cell lung cancer (NSCLC) can be delivered sequentially (sCRT) or concurrently (cCRT). Without high-volume data, current guidelines recommend either option for patients with negative margins (M−) and cCRT for those with positive margins (M+). In this study, survival was compared between sCRT versus cCRT for M− and M+ disease; survival in patients who underwent sCRT was also assessed with chemotherapy-first versus radiotherapy (RT)-first. Methods: The National Cancer Database was queried for patients with primary NSCLC undergoing surgery followed by CRT. Patients were excluded if they received neoadjuvant chemotherapy or RT. Both M− and M+ (including R1 and R2) subcohorts were evaluated. Multivariable logistic regression ascertained factors associated with cCRT delivery. Kaplan-Meier analysis evaluated overall survival (OS); Cox proportional hazards modeling determined variables associated with OS. Propensity score matching aimed to address group imbalances and indication biases. Results: Of 4,921 total patients, 3,475 (71%) were M−, 1,446 (29%) were M+, 2,271 (46%) received sCRT, and 2,650 (54%) underwent cCRT. Median OS among the sCRT and cCRT groups in patients who were M− was 54.6 versus 39.5 months, respectively (P<.001); differences persisted following propensity score matching (P<.001). In the overall M+ cohort, outcomes for sCRT and cCRT were 36.3 versus 30.5 months (P=.011), but showed equipoise following matching (P=.745). In the R1 and R2 subsets, no differences in OS were seen between cohorts (P=.368 and .553, respectively). When evaluating the sCRT population, there were no OS differences between chemotherapy-first and RT-first after matching (P=.229). Conclusions: Postoperative sCRT was associated with improved survival compared with cCRT in patients with M− disease, with statistical equipoise in those with M+ disease. Differential sequencing of sCRT does not appear to affect survival.
Michael J. Baine, Richard Sleightholm, Beth K. Neilsen, David Oupický, Lynette M. Smith, Vivek Verma and Chi Lin
Background: Despite the fact that stereotactic body radiation therapy (SBRT) is the only recommended first-line therapy for inoperable early-stage non–small cell lung cancer (NSCLC), several thermal ablative procedures (TAPs; defined herein as laser/cryoablation and electrocautery) are available. Studies showing outcomes of these procedures and how they compare with SBRT are scarce. We sought to evaluate the comparative efficacy of SBRT versus TAPs using the National Cancer Database (NCDB). Methods: The NCDB was queried for patients with early-stage NSCLC who did not undergo surgical resection. Treatment-specific inclusion criteria were applied to select for patients receiving either TAPs or SBRT. Univariate logistic regression and Cox proportional hazards modeling were performed, and Kaplan-Meier curves were generated. Serial propensity matches were performed using a modified greedy 8→n matching 1:1 algorithm. Results: A total of 27,734 patients were analyzed; 26,725 underwent SBRT and 1,009 underwent TAPs. Patients who received SBRT were older and more likely to have clinical stage IB (vs IA) disease. Despite this, SBRT was associated with longer median overall survival (mOS; 37.7 vs 33.5 months; P=.001) and 1-, 2-, and 5-year OS rates compared with the TAPs cohort (86.7% vs 83.1%, 67.5% vs 62.7%, and 30.6% vs 26.9%, respectively; P=.001). Upon propensity matching, improved OS with SBRT remained, with a mOS of 40.4 versus 33.4 months and 1-, 2-, and 5-year OS rates of 89.0% versus 82.9%, 69.7% versus 62.7%, and 34.4% versus 26.4%, respectively (P=.003). Conclusions: Despite being associated with more higher-risk factors, SBRT was associated with higher OS compared with TAPs for treatment of nonoperative patients diagnosed with early-stage NSCLC. However, causation cannot be implied owing to the inherent limitations of large heterogeneous datasets such as the NCDB.