Pathologic complete response rate after neoadjuvant chemoradiation in patients with locally advanced rectal cancer affects survival in patients with prolonged radiation-surgery interval

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Background: The current standard of care in locally advanced rectal cancer is neoadjuvant chemoradiation and R0 resection. An optimal radiation-surgery interval (RSI) has not been established. A small institutional dataset showed RSI > 49 days improved pathologic complete response (pCR) rates and disease free survival. However, in a national dataset, RSI greater than 60 days was associated with increased rates of positive margins and impaired overall survival. Because pCR is associated with improved survival, we used a national database to evaluate the relationship between RSI, pCR and survival after neoadjuvant therapy for rectal cancer. Methods: The NCDB was queried for cases 2004-2013 of AJCC stage II or III rectal adenocarcinoma that underwent neoadjuvant radiation followed by radical resection. We excluded patients with missing and outlier RSI. pCR was defined as ypT0N0M0. Chi-square, univariate, multivariable Cox model, and Cochran-Armitage time trend analyses were performed. Results: 23475 patients were identified. 7901 (33.7%) had RSI ≥60 days. pCR occurred in 1766 (11.3%) of the < 60 group and 1174 (14.9%) of the ≥60 group (p < 0.001). RSI ≥60 days has increased over time, from 22.1% in 2004 to 45.4% in 2013 (p < 0.001), as have pCR rates, from 8.4% in 2004 to 14.2% in 2013 (p < 0.001). Multivariable Cox model of the total cohort showed that RSI ≥60 days (HR = 1.11, 95% CI = 1.04-1.19) and residual disease (HR = 2.04, 95% CI = 1.78-2.34) were associated with increased mortality. Subgroup analysis of patients with pCR showed RSI ≥60 days was not associated with worse survival (HR = 1.07, 95% CI = 0.82-1.41). However, analysis of patients with residual disease showed RSI ≥60 days was associated with worse survival (HR = 1.13, 95% CI = 1.06-1.21). Conclusions: In a large national database, RSI ≥60 days worsens survival in patients who have residual disease after neoadjuvant therapy for locally advanced rectal cancer, while there is no difference in those with pCR. Emphasis should be placed on identifying patients who are unlikely to have pCR and to prioritize resection in these patients within 60 days of completion of chemoradiation.

Trends in utilization of chemotherapy and radiation for resectable gastric adenocarcinoma: An NCDB analysis

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Background: Locally advanced gastric adenocarcinoma (GACa) is optimally treated with a combination of surgery, chemotherapy (CHEMO) and radiation (RT). Utilization of therapies can vary with institutional practices. Methods: The NCDB was queried for pts with GACa who had RO resection (2006-2012). Pts with metastatic disease, incomplete pathologic staging, and incomplete CHEMO or RT sequencing data were excluded. Pts were divided into groups by treatment regimen: G1: perioperative CHEMO; G2: adjuvant CHEMO±RT; G3: neoadjuvant CHEMORT; G4: other adjunctive regimens; G5: surgery only. Pts who received neoadjuvant therapy were staged using clinical TNM; those who did not or had incomplete clinical staging were staged using pathologic TNM. 3 subsets were created: LOCAL: T0-2N0, LOCALLY ADV: T3-4N0, REGIONAL: N+. Chi-square, univariate, multivariable with stepwise selection, and Cochran-Armitage time trend analyses were performed. Results: N = 12946: G1 = 1099, G2 = 4771, G3 = 180, G4 = 244 and G5 = 6652. The percentage of pts receiving adjunctive therapy was determined for each subset: LOCAL = 17.2%, LOCALLY ADV = 59.8%, and REGIONAL = 66.0%. Use of adjunctive therapy increased from 2006: 44% to 2012: 53% (p < 0.01). Use of perioperative CHEMO increased from 2006: 4% to 2012: 18% (p < 0.01). Factors affecting use of adjunctive therapy on multivariable analysis are: age (p < 0.01), race (p < 0.01), income (p < 0.01), insurance (p < 0.01), comorbidity score (p < 0.01), and facility volume (p = 0.01). Conclusions: Though utilization of adjunctive therapy is increasing, a large proportion of pts with resectable GACa do not receive recommended adjunctive therapy. This study highlights disparities in utilization of optimal multimodality care. National efforts to expand access to care are necessary to improve outcomes in resectable GACa. [Table: see text]

Utilization of primary chemoradiotherapy for anal squamous cell carcinoma in the elderly: An analysis of the NCDB

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Background: Definitive chemoradiotherapy (CHEMORT) is the treatment of choice for anal squamous cell carcinoma (SCC), while surgery is typically reserved for salvage therapy. Patients (pts) who are frail due to advanced age or medical comorbidities often have difficulty completing therapy. Methods: The NCDB was queried for pts with anal SCC (2004-2012). Pts < 50 years, and those with in situ or metastatic disease, or with incomplete CHEMORT treatment data were excluded. The primary outcome was completion of CHEMORT. Secondary outcome was requirement of salvage surgical therapy. Statistical analyses include Chi-square, univariate and multivariable logistic regression. Results: N = 11918. 5907 (49.5%) did not complete recommended CHEMORT. 9862 (82.8%) received CHEMO, 6011 (61.0%) of whom completed RT with dosage > 45Gy. Factors significantly associated with failure to complete therapy on multivariable analysis include: older age at diagnosis, higher Charlson-Deyo score, earlier year of diagnosis, male gender, and earlier clinical T and N stages (Table 1). 41.7% of pts who did not complete CHEMORT required salvage surgical therapy, versus 25.1% of pts completing CHEMORT (OR: 2.14 95% CI [1.97, 2.31], p < 0.01). Conclusions: Approximately half of pts older than 50 years of age with anal SCC failed to complete definitive CHEMORT. This study highlights the negative impact of frailty on the ability of pts to receive optimal therapy, resulting in more operative interventions. Medical optimization of older pts with more comorbidities in order to improve utilization of CHEMORT is one possible area of improvement in the management of anal SCC. [Table: see text]