Institutional variation in the thoroughness of pathologic assessment and pathologic complete response rates for locally advanced rectal cancers treated with neoadjuvant chemoradiation.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 696-696
Author(s):  
Oliver S Chow ◽  
Sujata Patil ◽  
Metin Keskin ◽  
Jesse Joshua Smith ◽  
Maria Widmar ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Tumor Size ◽  
Anal Verge ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Multivariable Analysis ◽  
Residual Tumor ◽  
Complete Response ◽  
Neoadjuvant Chemoradiation ◽  
Pathologic Assessment

696 Background: A pathologic complete response (pCR) after neoadjuvant therapy and surgical excision is associated with a better prognosis and guides the management of patients with locally advanced rectal cancer. It is not known whether the thoroughness of pathologic assessment correlates with the finding of pCR. Methods: We introduce a surrogate measure for the thoroughness of pathologic assessment by taking the ratio of maximum residual tumor size and the number of cassettes prepared from the tumor: the Tumor Size to Cassette Ratio (TSCR). We retrospectively reviewed pathology reports from 259 patients with Stage II/III rectal cancer enrolled in a multicenter prospective clinical trial to determine whether TSCR is associated with pCR. Results: Of 247 included patients, 71 (29%) had a pCR. The pCR rate ranged from 0-45% and TSCR ranged from 0.0004 to 1.67 across the twelve trial sites. TSCR was significantly associated with pCR on univariable analysis. On multivariable analysis, TSCR remained significantly associated with pCR (odds ratio of 0.05; 95% CI 0.008-0.302) after adjusting for clinical stage, tumor size, distance from anal verge, radiation dose, and the number of neoadjuvant cycles of FOLFOX received. Conclusions: Pathologists tend to assess rectal cancer specimens with a pCR more thoroughly, but the thoroughness of pathologic assessment of residual tumor specimens varies between institutions. The thoroughness of pathologic assessment is associated with pCR. This raises the need for further standardization in the assessment of rectal cancer specimens after neoadjuvant chemoradiation.

Microsatellite instability (MSI) as an independent predictor of pathologic complete response (PCR) in locally advanced rectal cancer: A National Cancer Database (NCDB) analysis.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 616-616 ◽  
Author(s):  
Shaakir Hasan ◽  
Paul Renz ◽  
Rodney E Wegner ◽  
Gene Grant Finley ◽  
Moses S. Raj ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Microsatellite Instability ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Multivariable Analysis ◽  
Complete Response ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Neoadjuvant Chemoradiation ◽  
National Cancer Database

616 Background: The relationship between microsatellite instability (MSI) and response to neoadjuvant chemoradiation in rectal cancer is not well understood. We therefore utilized the national cancer database (NCDB) to investigate the association between MSI and pathologic complete response (pCR) in this patient population. Methods: We analyzed 5,086 patients between 2010-2015 with locally advanced rectal cancer who were tested for MSI and treated definitively with chemoradiation followed by surgery. Primary comparison groups were between 4,450 MSI-negative(-) and 636 MSI-positive(+) patients. Multivariable regression analysis was conducted to identify demographic, therapeutic, and clinical characteristics predictive of pCR. Cox proportional hazard ratios were used for survival. Results: All patients were treated with definitive chemoradiation (median dose 50.4 Gy) followed by resection within 4 months. MSI(+) patients were associated with earlier year of diagnosis and higher grade tumors (P < 0.05). The overall pCR rate was 8.6%, including 8.9% for MSI(-) and 5.9% for MSI(+) tumors (P = 0.01). Along with lower T stage, MSI(+) cases were significantly associated with a reduced pCR rate (OR = 0.65, 95% CI 0.43 – 0.96) with multivariable analysis. The 5-year survival for patients with pCR was 93% compared to 73% without it (< 0.001). Conclusions: Microsatellite instability was independently associated with a reduction in pathologic complete response for locally advanced rectal cancer following neoadjuvant chemoradiation in this NCDB-based analysis.[Table: see text]

Assessment of macroscopic features in relation to tumor response to neoadjuvant chemoradiation therapy in rectal cancer.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 507-507
Author(s):  
Amanda Kathleen Arrington ◽  
Julio Garcia-Aguilar ◽  
Marjun Philip Duldulao ◽  
Carrie Luu ◽  
Julian Sanchez ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Tumor Response ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Neoadjuvant Chemoradiation ◽  
Chemoradiation Therapy ◽  
Oncologic Outcomes ◽  
Neoadjuvant Chemoradiation Therapy ◽  
Pathologic Features

507 Background: Several studies show locally advanced rectal cancer patients with clinical complete response (cCR) have comparable oncologic outcomes to pathologic complete response (pCR) to neoadjuvant chemoradiation therapy (NCRT). Thus, total mesorectal excision (TME) could potentially be avoided. Our objective was to validate macroscopic features of cCR. Methods: 164 patients with stage II/III rectal cancer were previously enrolled in a phase II trial and treated by NCRT and TME. Tumor response in the surgical specimens was assessed according to AJCC guidelines. A pCR was defined as absence of viable tumor cells. Gross macroscopic features by the pathologist were tabulated and our cohort was applied to previously published cCR criteria. Results: 25.0% (n = 41) had pCR; 75.0% (n = 123) had non-pCR. Descriptors were condensed into 14 macroscopic features by combining terms and excluding those rarely mentioned. Several reports affirm that scarring signifies cCR, while others suggest that fibrosis, edema, ulceration and nonpalpable tumor to be consistent with cCR. In our study, scarring was found in 6.1% of patients, 16.7% of which had pCR. We found that hyperemia, scarring, flat, smooth, and tan-pink mucosa were significantly associated with pCR (p < 0.05). In contrast, a firm lesion and ulceration were frequently observed in patients with non-pCR (p = 0.02 and 0.05 respectively). Conclusions: Our study suggests that macroscopic pathologic features do correlate with pCR. Although cCR has comparable oncologic outcomes as pCR with favorable outcomes, standard criteria of cCR should first be defined so NCRT patients can safely be selected for observation only. [Table: see text]

Totally neoadjuvant chemoradiation therapy with mFOLFOX6 in locally advanced rectal cancer: A single arm phase II study (FOTAC).

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. TPS816-TPS816
Author(s):  
Jianwei Zhang ◽  
Yue Cai ◽  
Huabin Hu ◽  
Jian Xiao ◽  
Dianke Chen ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Phase Ii Study ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Neoadjuvant Chemoradiation ◽  
Chemoradiation Therapy ◽  
Neoadjuvant Chemoradiation Therapy

TPS816 Background: Preoperative 5-Fluorouracil based chemoradiotherapy is the standard of treatment for locally advanced rectal cancer. About 15% to 18% of patients would achieve pathologic complete response (pCR) after 5-Fluorouracil based chemoradiation. And the survival outcome of patients with pCR was much better than that of non-pCR. In our previous FOWARC study, in the group of preoperative systemic chemotherapy with mFOLFOX6 combined with radiation, the pCR rate was up to 27.5%. In another study, adding mFOLFOX6 after neoadjuvant chemo radiation in locally advanced rectal cancer improve the pCR rate to 38%. This phase II study aimed to explore whether totally neoadjuvant chemoradiation therapy with mFOLFOX6 could further improve the pCR rate in locally advanced rectal cancer. Methods: The primary endpoint is the pathologic complete response rate (pCR).The secondary endpoint included 3-year disease free survival rate, 3-year local recurrence rate, and safety. We hypothesized that totally neoadjuvant chemoradiation therapy with mFOLFOX6 could improve the pCR rate from 18% to 45% with 5% type I error and 80% power. Fifty patients met inclusion criteria will be enrolled in the trial. All patients will receive long term radiation for 25 times and 50Gy before surgery. Four cycles of mFOLFOX6 would be performed every 2 weeks during radiotherapy, and another 4-6 cycles would be added after radiotherapy and before operation. Totally, the patients will receive 8-10 cycles of chemotherapy before surgery. MRI of the pelvic will be performed every 4 cycles of the therapy to assess clinical response. Then the patient will receive total mesorectal excision at least 8 weeks after radiotherapy. The post-operative chemotherapy will be omitted and all the patients go to surveillance. Clinical trial information: NCT02887313.

Association of adjuvant chemotherapy with improved overall survival for patients with locally advanced rectal cancer (LARC) who achieve a pathologic complete response (pCR) to neoadjuvant chemoradiation (nCRT).

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 716-716
Author(s):  
Danish Shahab ◽  
Emmanuel M. Gabriel ◽  
Kristopher Attwood ◽  
Valerie Francescutti ◽  
Wen Wee Ma ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Overall Survival ◽  
Adjuvant Chemotherapy ◽  
Adjuvant Therapy ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Neoadjuvant Chemoradiation ◽  
Comorbidity Score ◽  
N Stage

716 Background: 15-20% of patients with locally advanced rectal adenocarcinoma (LARC) achieve a pathologic complete response (pCR) following neoadjuvant chemoradiation (nCRT). The role of adjuvant chemotherapy has been questioned. Methods: Patients with rectal cancer receiving nCRT in the National Cancer Data Base (NCDB) 2006-2013 data set were evaluated. The primary outcome was overall survival (OS). The association between OS and patient characteristics were examined using multivariable Cox regression models. Results: 2,903 patients were identified who achieved a pCR. The median follow up was 43.2 months. 2,102 received nCRT and 789 received nCRT + adjuvant chemotherapy. Factors significantly associated with OS included age (p<0.001), gender (p=0.011), Charlson-Deyo comorbidity score (CDI) (p<0.001), grade (p=0.029), clinical T stage (p=0.030), and CEA negativity (p=0.002), but not nodal status. The 3-year OS rate was 94% in the adjuvant therapy group as compared to 84% in the nCRT alone group (p<0.001). In considering clinical N-stage, the benefit was comparable for both N+ and N- tumors. Adjuvant chemotherapy was more likely to be given for younger patients (age < 60), lower comorbidity score, higher grade, positive CEA status, higher clinical T stage, and higher clinical N stage. When stratifying by these factors, similar benefits in OS were observed in the adjuvant cohort. Conclusions: Following nCRT and achievement of a pCR, the receipt of adjuvant chemotherapy is associated with improved OS. Patients receiving adjuvant therapy were more likely to be younger and have a low CDI, but have more advanced stage disease. Thus, a selection bias may be present. Nonetheless, in the setting of the already excellent outcome associated with pCR, the additional benefit of adjuvant chemotherapy should be weighed against toxicity.

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

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3608-3608
Author(s):  
Benjamin Mitchell Motz ◽  
Patrick Daniel Lorimer ◽  
Danielle Boselli ◽  
I'sis N Perry ◽  
Joshua S. Hill ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Residual Disease ◽  
Cox Model ◽  
Locally Advanced ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Neoadjuvant Chemoradiation ◽  
National Database

3608 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.

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