Factors influencing response to neoadjuvant chemoradiation and outcomes in rectal cancer patients: tertiary Indian cancer hospital experience

Molecular subtype identification and prognosis stratification by a immunogenic cell death-related gene expression signature in colorectal cancer

OBJECTIVES

This study intended to develop a new immunogenic cell death (ICD)-related prognostic signature for colorectal cancer (CRC) patients.

RESEARCH DESIGN AND METHODS

The Non-Negative Matrix Factorization (NMF) algorithm was adopted to cluster tumor samples based on ICD gene expression to obtain ICD-related subtypes. Survival analysis and immune microenvironment analysis were conducted among different subtypes. Regression analysis was used to construct the model. Based on riskscore median, cancer patients were classified into high and low risk groups, and independent prognostic ability of the model was analyzed. The CIBERSORT algorithm was adopted to determine the immune infiltration level of both groups.

RESULTS

We analyzed the differential genes between cluster 4 and cluster 1-3 and obtained 12 genes with the best prognostic features finally (NLGN1, SLC30A3, C3orf20, ADAD2, ATOH1, ATP6V1B1, KCNQ2, MUCL3, RGCC, CLEC17A, COL6A5, and INSL4). In addition, patients with lower risk had higher levels of infiltration of most immune cells, lower Tumor Immune Dysfunction and Exclusion (TIDE) level and higher immunophenscore (IPS) level than those with higher risk.

CONCLUSIONS

This study constructed and validated the ICD feature signature predicting CRC prognosis and provide a reference criteria for guiding the prognosis and immunotherapy of CRC cancer patients.

Native T1 mapping for differentiating the histopathologic type, grade, and stage of rectal adenocarcinoma: a pilot study

Background

Previous studies have indicated that T1 relaxation time could be utilized for the analysis of tissue characteristics. T1 mapping technology has been gradually used on research of body tumor. In this study, the application of native T1 relaxation time for differentiating the histopathologic type, grade, and stage of rectal adenocarcinoma was investigated.

Methods

One hundred and twenty patients with pathologically confirmed rectal adenocarcinoma were retrospectively evaluated. All patients underwent high-resolution anatomical magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and T1 mapping sequences. Parameters of T1 relaxation time and apparent diffusion coefficient (ADC) were measured between the different groups. The diagnostic power was evaluated though the receiver operating characteristic (ROC) curve.

Results

The T1 and ADC values varied significantly between rectal mucinous adenocarcinoma (MC) and non-mucinous rectal adenocarcinoma (AC) ([1986.1 ± 163.3 ms] vs. [1562.3 ± 244.2 ms] and [1.38 ± 0.23 × 10⁻³mm²/s] vs. [1.03 ± 0.15 × 10⁻³mm²/s], respectively; P < 0.001). In the AC group, T1 relaxation time were significantly different between the low- and high-grade adenocarcinoma cases ([1508.7 ± 188.6 ms] vs. [1806.5 ± 317.5 ms], P < 0.001), while no differences were apparent in the ADC values ([1.03 ± 0.14 × 10⁻³mm²/s] vs. [1.04 ± 0.18 × 10⁻³mm²/s], P > 0.05). No significant differences in T1 and ADC values were identified between the different T and N stage groups for both MC and AC (all P > 0.05).

Conclusions

Native T1 relaxation time can be used to discriminate MC from AC. The T1 relaxation time was helpful for differentiating the low- and high-grade of AC.

Factors influencing downstaging after neoadjuvant long-course chemoradiotherapy in rectal carcinoma

PURPOSE

This single-centre cohort study was designed to identify factors that can predict primary tumour downstaging by neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

METHODS

Prospectively collected data from 555 patients with clinical T category (cT) cT3-4 rectal carcinoma treated between 1995 and 2019 were retrospectively analysed. All patients received long-term neoadjuvant chemoradiotherapy followed by surgery with curative intent at the Department of Surgery, University Hospital Erlangen, Germany. Patient-, tumour- and treatment-related factors with a potential impact on the downstaging of rectal carcinoma to pathological T category (pT) ≤ ypT2 and ypT0 were analysed in univariate and multivariate logistic regression analyses. The prognosis of patients with and without downstaging of the primary tumour was compared.

RESULTS

A total of 288 (51.9%) patients showed downstaging to ≤ ypT2. Eighty-six (15.5%) patients achieved clinical complete regression (ypT0). In the multivariate logistic regression analysis, the factors cT category, BMI, ECOG score, CEA, histological type, extension in the rectum and year of the start of treatment were found to be independent factors for predicting downstaging to ≤ ypT2 after neoadjuvant chemoradiotherapy. The year of treatment initiation also remained an independent significant predictor for pathological complete regression. The prognosis was superior in patients with downstaging to ≤ ypT2 in terms of locoregional and distant recurrence as well as disease-free and overall survival.

CONCLUSION

Factors predicting downstaging after long-term nCRT could be identified. This may be helpful for counselling patients and selecting the optimal treatment for patients with advanced rectal carcinoma.

MRI features of signet ring rectal cancer

PURPOSE

Signet Ring Rectal Cancer (SRRC) of rectum is rare high-grade subtype with poor prognosis and characteristic histopathology. We evaluated its imaging appearance and correlated its outcomes.

MATERIALS AND METHODS

We conducted a retrospective review of the rectal MRIs of 97 patients with rectal SRRC, evaluating tumor morphology, T2 signal, length, location, pattern of tumor growth, nodal status and location, EMVI (extramural vascular invasion), site of metastases, and response to chemotherapy. The tumor signal on T2W images was categorized into intermediate, T2 hyperintense, and fluid/mucin bright. Imaging findings were correlated with risk of metastatic/ recurrent disease, disease-free survival, and overall survival.

RESULTS

The median age of patients of SRRC in our study was 35 years and more frequently found in male patients. The common imaging features of SRRC were T2-hyperintense signal (63%), infiltrative growth pattern (76%), positive MR CRM (Circumferential Resection Margin on MRI) (84%), presence of EMVI (51%), and advanced T and N stage (97% and 84%, respectively). Peritoneum and nodes were the most common sites of metastases. Raised serum CEA (Carcino-embryonic Antigen) levels, positive MR CRM status, extramesorectal adenopathy, and advanced N stage had statistically significant predictive value for recurrence or metastases. Elevated serum CEA levels (p = 0.019) and intermediate T2 signal (p = 0.012) demonstrated significant independent association with poor overall survival, while advanced N stage (p = 0.033) demonstrated significant independent association with worse disease-free survival in multivariate analysis.

CONCLUSION

SRRC affected young patients and demonstrated T2-hyperintense signal and subepithelial spread in an infiltrative pattern. Elevated CEA levels and T2-intermediate signal intensity are independent predictors for worse overall survival and advanced nodal stage is independent prognostic factor of poor disease-free survival. MRI rectum can pinpoint the pathology given the distinct MRI morphology and age of presentation.

Prognostic Value of Pretreatment Serum CA199 in Patients with Locally Advanced Rectal Cancer Treated with CRT Followed by TME with Normal Pretreatment Carcinoembryonic Antigen Levels

BACKGROUND

Elevated pretreatment carcinoembryonic antigen (CEA) levels are related to poor prognosis in patients with locally advanced rectal cancer (LARC) treated with neo-CRT followed by TME. In patients with normal pretreatment CEA levels, the prognostic significance of carbohydrate antigen 199 (CA199) is controversial.

OBJECTIVES

The aim of this study was to explore the prognostic value of pretreatment serum CA199 in patients with LARC who had normal pretreatment CEA levels treated with neo-CRT followed by curative surgery.

METHODS

A retrospective study of 456 patients with LARC treated with neo-CRT followed by TME between January 2006 and May 2017 was performed. We employed the maximal χ2 method to determine the CA199 threshold of 9.1 U/mL based on the difference in survival and divided patients into 2 groups. Group 1: patients with pretreatment s-CEA < 5 ng/mL and CA199 ≥ 9.1 U/mL. Group 2: patients with pretreatment s-CEA < 5 ng/mL and CA199 < 9.1 U/mL. Overall survival (OS) across CA199 was assessed using Cox proportional hazard regression models (PS:CEA ≥ 5 ng/mL was seen as elevated).

RESULTS

Multivariate analyses demonstrated that the following factors were significantly related to OS in patients with LARC with normal pretreatment CEA levels: ypT (odds ratio [OR] 1.863, p = 0.030), ypN (OR 1.622, p = 0.026), and pretreatment CA199 levels (OR 1.886, p = 0.048).

CONCLUSION

Pretreatment CA199 is an independent factor for OS in patients with LARC with normal pretreatment CEA levels, which may reach the clinic to guide individualized decision-making.

Impact of delaying surgery after chemoradiation in rectal cancer: outcomes from a tertiary cancer centre in India

Background

Delaying surgery after chemoradiation is one of the strategies for increasing tumor regression in rectal cancer. Tumour regression and PCR are known to have positive impact on survival.

Methods

It's a retrospective study of 161 patients undergoing surgery after neoadjuvant chemoradiation (NCRT) for locally advanced rectal cancer (LARC). Patients were divided into three categories based on the gap between NCRT and surgery, i.e., <8, 8-12 and >12 weeks. Tumor regression grades (TRG), sphincter preservation, post-operative morbidity-mortality and survival were evaluated.

Results

Sphincter preservation was significantly less in >12 weeks group compared to the other two groups (P=0.003). Intraoperative blood loss was significantly higher in >12 weeks group compared to 8-12 weeks group (P=0.001).There was no difference in major postoperative morbidity and hospital stay among the groups. There was no significant correlation between delay and TRG (P=0.644). At Median follow up of 49.5 months the projected 3-year overall survival (OS) and disease free survival (DFS) were not significantly different among the 3 groups (OS: 79.5% vs. 83.3% vs. 76.5%; P=0.849 and DFS 50.4% vs. 70.6% vs. 62%; P=0.270 respectively).

Conclusions

Delaying surgery by more than 12 weeks causes more blood loss but no change in morbidity or hospital stay. Increased time interval between radiation and surgery does not improve tumor regression and has no effect on survival.

Efficacy of preoperative chemoradiotherapy in downstaging rectal cancer and its impact on the long-term outcome

Introduction:

Response to preoperative chemoradiation (PRTCT) for rectal cancer predicts the long-term outcome.

Context:

Tertiary care hospital.

Aims:

The aim is to study the factors affecting the response to chemoradiation.

Settings and Design:

Retrospective.

Materials and Methods:

Twenty-three patients of rectal cancer undergoing PRTCT followed by surgery and adjuvant chemotherapy were followed up for 20–56 months. Postoperative response, tumor downstaging and nodal downstaging were correlated with the disease status.

Results:

Tumor downstaging was seen in 11 (50%) and nodal downstaging in 12 (63.15%) patients. Nodal downstaging was statistically significant with P = 0.004. Pathological complete response (PCR) was seen in one patient and partial response (PR) in 17 patients. Thirteen (72.2% of patients) were alive and disease free and the negative nodal status correlated with long-term control with P = 0.04.

Conclusion:

Most patients of rectal cancer show PR to PRTCT, and the benefit is more for node-positive patients. Nodal PCR is associated with a higher chance of long-term disease control.

Low prevalence of deficient mismatch repair (dMMR) protein in locally advanced rectal cancers (LARC) and treatment outcomes

Background

The available evidence in locally advanced rectal cancer (LARC) suggests a low prevalence of deficient mismatch repair (dMMR) protein status, approximating 1-3%.

Methods

Patients with LARC who were offered long course chemoradiation (LCRT), as per institution protocol during the period of 1st January 2014 to 31st December 2015 at Tata Memorial Hospital (TMH) in Mumbai were evaluated for outcomes and assessment of MMR status.

Results

A total of 419 patients were evaluated for LARC in TMH, of whom 354 were treated with LCRT. Of these 354 patients, 296 were assessable for MMR status based on tissue adequacy for testing. Three patients (1.01%) has dMMR status, while the remaining 293 patients had proficient MMR status. A total of 240 patients (67.8%) underwent curative intent resections. With a median follow-up of 32 months, estimated 3-year recurrence free survival (RFS) and overall survival (OS) for the resected group was 63.5% and 85.2%, respectively, while 3-year event free survival and OS for the unresected cohort was 15.2% and 15.8%, respectively. Signet ring histology, higher ypT stage, involved margin status post resection, and delays (>1 week) in LCRT were associated with inferior OS on multivariate analysis.

Conclusions

In a large LARC cohort, a majority of tumors had proficient MMR status, suggesting that MSI as a biomarker may have limited applicability in the management of rectal cancers. Signet ring histology, CRM involvement post resection, higher ypT stage and interruptions in LCRT predicted for inferior OS.

Pre-treatment carcinoembryonic antigen and outcome of patients with rectal cancer receiving neo-adjuvant chemo-radiation and surgical resection: a systematic review and meta-analysis

Neo-adjuvant chemo-radiation is the standard of care for patients with locally advanced rectal carcinoma. The aim of the present paper is to evaluate the relationship of the baseline serologic concentration of the carcinoembryonic antigen with the outcome. Data sources included MEDLINE and Web of Science databases. A systematic search of the databases by a predefined criterion has been conducted. Chemo-radiation followed by surgical resection of rectal tumors was the intervention of interest. From selected studies, the relationships between carcinoembryonic antigen and pathologic complete response, disease-free survival and overall survival were assessed. Carcinoembryonic antigen correlated significantly and inversely with the rate of pathologic complete responses (OR 2.00). Similar to this relationship, a low baseline carcinoembryonic antigen concentration was associated with a better disease-free survival (OR 1.88) and a better overall survival (OR 1.85). Heterogeneity of studies and publication bias were considerable in evaluating the relationship of baseline carcinoembryonic antigen and pathologic complete response. Baseline carcinoembryonic antigen should be regarded as a predictor of outcome of patients undergoing neo-adjuvant chemo-radiation. A calibration of the cutoff value from 5 to 3 ng/ml appears more appropriate to this patient population and should be evaluated in prospective trials.

Pre- and post-surgery treatments in rectal cancer: a long-term single-centre experience

BACKGROUND

Our study evaluated long-term survival outcomes in rectal cancer patients treated with preoperative radiotherapy, and the impact on survival of concomitant and postoperative adjuvant chemotherapy (ctx), among other prognostic factors.

METHODS

The study included 196 patients [median age: 58 years (range: 20-86 years); 63.0% men] with locally advanced rectal carcinoma and, in some cases, resectable liver metastasis. Rates of distant metastasis and local recurrence and of 5-year distant metastasis-free survival (dmfs) and overall survival (os) were determined.

RESULTS

The 5-year os rate was 57.0%, with a median duration of 81.5 months (95% confidence interval: 73.7 months to 89.4 months), and the 5-year dmfs rate was 54.1%, with a median duration of 68.4 months (95% confidence interval: 40.4 months to 96.4 months). Prognostic factors for higher os and dmfs rates were downstaging (p = 0.013 and p = 0.005 respectively), radiotherapy dose (50 Gy vs. 56 Gy or 45-46 Gy, both p = 0.002), and concomitant ctx use (p = 0.004 and p = 0.001) and type (5-fluorouracil-leucovorin-folinic acid vs. tegafur-folinic acid, p = 0.034 and p = 0.043). Adjuvant ctx after neoadjuvant long-term concomitant chemoradiotherapy (ccrt) and surgery was associated with better 5-year os rates for postoperative T0-T3 disease (p = 0.003) and disease at all lymph node stages (p = 0.001).

CONCLUSIONS

Our findings revealed a favourable survival outcome with long-term fractionated irradiation and concomitant 5-fluorouracil-based ctx, achieving 5-year os and dmfs rates of 57.0% and 54.1% respectively. Preoperative administration of radiotherapy (50 Gy) and postoperative adjuvant ctx were associated with a significant survival benefit. Radiation doses above 50 Gy and the interval between ccrt and surgery had no significant effect on survival.

Gastrointestinal cancers in India: Treatment perspective

GI cancer is not one cancer but is a term for the group of cancers that affect the digestive system including gastric cancer (GC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), esophageal cancer (EC), and pancreatic cancer (PC). Overall, the GI cancers are responsible for more cancers and more deaths from cancer than any other organ. 5 year survival of these cancers remains low compared to western world. Unlike the rest of the world where organ based specialities hepatobiliary, pancreatic, colorectal and esophagogastric exist, these cancers are managed in India by either a gastrointestinal surgeons, surgical oncologist, or a general surgeon with varying outcomes. The aim of this review was to collate data on GI cancers in indian continent. In colorectal cancers, data from tertiary care centres identifies the unique problem of mucinous and signet colorectal cancer. Results of rectal cancer resection in terms of technique (intersphincteric resection, extralevator aper, minimal invasive approach) to be comparable with world literature. However long term outcome and data regarding colon cancers and nationally is needed. Gastric cancer at presentation are advanced and in surgically resected patients, there is need for a trial to compare chemoradiation vs chemotherapy alone to prevent loco regional recurrence. Data on minimal invasive gastric cancer surgery may be sparse for the same reason. Theree is a lot of data on surgical techniques and perioperatve outcomes in pancreatic cancer. There is a high volume of locally advanced gallbladder cancers with efforts on to decide whether neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy is better for down staging. Considering GI cancers, a heterogeneous disease with site specific treatment options and variable outcomes, the overall data and outcomes are extremely variable. Young patients with pathology unique to the Indian subcontinent (for example, signet ring rectal cancer, GBCs) need focussed attention. Solution for such pathology needs to come from the Indian continent itself. Joint efforts to improve outcomes for GI cancer can be integrated under the national cancer grid program.