Successful Salvage of Partial Gastric Conduit Necrosis by Primary Anastomosis in a Post-Esophagectomy Patient

Gastric conduit necrosis is a rare but severe complication of esophageal surgery, often associated with mediastinal sepsis and high morbidity and mortality rates, as well as reduced efficacy of conservative treatments. In most cases, management involves salvage therapy, including fluid resuscitation, antibiotics, aggressive debridement, drainage of infected collections, and proximal esophageal diversion. Primary anastomosis is rarely performed. We describe a successful case wherein we salvaged a patient following a McKeown esophagectomy and gastric pull-up, who developed partial full-thickness necrosis of the gastric conduit postoperatively, along with pleural and mediastinal sepsis. We managed this situation through thoracic debridement, take-down of the anastomosis, resection of the devitalized segment of the conduit, and primary esophagogastric anastomosis. Conduit perfusion was demonstrated using ICG fluorescent angiography. This case illustrates that, once debridement and sepsis control are achieved, a primary anastomosis, if feasible, can be safely performed, potentially avoiding a two-step procedure and a second laparotomy/thoracotomy.

Evaluation of indocyanine green tracheobronchial fluorescence (ICG-TBF) via nebulization during minimally invasive esophagectomy

Surgical manipulation of the tracheobronchial complex is a contributing factor in pulmonary morbidity of esophagectomy. Accurate dissection between membranous trachea and bronchi with esophagus is essential. This study tests the feasibility of delivering indocyanine green (ICG) in an aerosol form to achieve tracheobronchial fluorescence (ICG-TBF). Patients with esophageal and esophagogastric junction carcinoma (N = 37) undergoing minimally invasive esophagectomy (McKeown type) were included. ICG was aerosolized by nebulization in supine position before thoracoscopy. ICG-TBF was observed with real-time fluorescence-enabled camera. Intra- and postoperative complications related to ICG were the primary focus. ICG-TBF was identified in 94.6% (35/37) of patients with median time to fluorescence identification of 15 minutes (range 1-43). There were no airway injuries in the study. The ICU median stay was 2 (range 2-21) days. No intra- or postoperative complications attributable to ICG were observed. Grade 3 or 4 pulmonary complications were seen in total 8.1% patients. No 90-day postoperative mortality was seen. ICG delivered in aerosol form was found to be safe and effective in achieving ICG-TBF. It aided in accurate dissection of esophagus from the tracheobronchial complex. Further studies on effect of ICG-TBF in decreasing pulmonary complications of esophagectomy are needed.

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Grossing to reporting of Wilms tumor with emphasis on proper sampling in treatment-naive and postchemotherapy specimens and their clinicopathological correlation with outcome

Context

Emphasis on grossing to reporting for the assessment of histopathological parameters predicting outcomes in Wilms tumor.

Aims

To analyze various clinicopathological parameters that effect outcomes in treatment naïve and post chemotherapy Wilms tumor specimens.

Settings and Design

This was a retrospective observational study.

Subjects and Methods

All patients diagnosed with Wilms tumor between 2012 and 2018 at our institute will be included with their clinical findings, laboratory reports, and radiological findings. The patients will be categorized into two groups based on treatment protocol (Society of Pediatric Oncology (SIOP) or the National Wilms Tumor Study Group/Children's Oncology Group (COG) guidelines) used. Details of Grossing and reporting protocols used for the in pre treatment and post treatment specimens will be analyzed. Follow-up till December 2020 will be analyzed.

Statistical Analysis Used

Chi-square and Fisher's exact tests were used for statistical analysis.

Results

A total of 36 patients with the diagnosis of Wilms tumor were included in the present study. The mean age of presentation was 3.9 ± 0.7 years, and males were more common than females. Most of them presented as abdominal mass and few with isolated hematuria. Twenty-six (72%) patients were treated under SIOP protocol with preoperative neoadjuvant chemotherapy. Ten patients underwent upfront surgery as per COG protocol. In SIOP group patients, the mean tumor size was 9.3cm. Forty percent (n = 10) we mixed histological type followed by blastemal type constituting (32%, n = 8). Regressive and epithelial histological types constituted 16% (n = 4) and 12% (n = 3), respectively. In the SIOP group 72% (n = 19) had no anaplasia and 28% (n = 7) had anaplasia. Fifty seven percent (n = 15) cases were Stage I, followed by 26.9% n = 7) and 11.5% (n = 3) being Stage II and Stage III, respectively. Ten patients underwent upfront surgery as per COG protocol. The mean tumor size among this group was 8 cm ranging from 7 cm to 11 cm. Eight (80%) cases had favorable histology and two cases showed focal anaplasia. Heterologous differentiation is seen in 3 (70%). Out of the 10 cases, one case was Stage I, six were Stage 2, one was Stage III, and two were clinical Stage IV. None of the cases showed either vessel or lymph node metastasis. All the patients received adjuvant chemotherapy postsurgery and were followed up till December 2020 for (at least 3 years). Of 25 patients in the SIOP group, 18 (72%) had complete remission with no radiological evidence of residual disease. Of the 10 patients in the COG group, 6 (70%) had complete remission.

Conclusions

Histopathological evaluation of Wilms tumor is a critical aspect in the management of Wilms tumor, as tumor characteristics are different in the tumors treated under SIOP and COG protocols, which will ultimately affect the prognostic risk stratification. This necessitates the knowledge of the important grossing and reporting of these tumors under the two protocols.

Management of Epirubicin Extravasation Injuries of the Hand with Debridement and Flap Cover-A Case Series

Chemotherapy extravasation injury is an iatrogenic injury due to extravasation of the drug from the vessel during infusion therapy. Among various chemotherapeutic drugs, DNA binding vesicants like epirubicin and doxorubicin can lead to extensive tissue necrosis following extravasation. They are commonly used in many chemotherapy regimens including those for carcinoma breast. We present our case series in the management of these wounds with aggressive debridement and regional (pedicled groin)/free flaps (superficial circumflex iliac artery perforator, lateral arm) for cover in five patients. All flaps healed well with patient returning to further treatment in 3 to 4 weeks post-surgery with preservation of hand function. Thus, early recognition of the type of drug that has extravasated is crucial. Regional and free flaps are superior to local flaps because there are no extra incisions and grafts on the limb that has already been injured.

Effect of Peritumoral Infiltration of Local Anesthetic Before Surgery on Survival in Early Breast Cancer

PURPOSE

Preventing metastases by using perioperative interventions has not been adequately explored. Local anesthesia blocks voltage-gated sodium channels and thereby prevents activation of prometastatic pathways. We conducted an open-label, multicenter randomized trial to test the impact of presurgical, peritumoral infiltration of local anesthesia on disease-free survival (DFS).

METHODS

Women with early breast cancer planned for upfront surgery without prior neoadjuvant treatment were randomly assigned to receive peritumoral injection of 0.5% lidocaine, 7-10 minutes before surgery (local anesthetics [LA] arm) or surgery without lidocaine (no LA arm). Random assignment was stratified by menopausal status, tumor size, and center. Participants received standard postoperative adjuvant treatment. Primary and secondary end points were DFS and overall survival (OS), respectively.

RESULTS

Excluding eligibility violations, 1,583 of 1,600 randomly assigned patients were included in this analysis (LA, 796; no LA, 804). At a median follow-up of 68 months, there were 255 DFS events (LA, 109; no LA, 146) and 189 deaths (LA, 79; no LA, 110). In LA and no LA arms, 5-year DFS rates were 86.6% and 82.6% (hazard ratio [HR], 0.74; 95% CI, 0.58 to 0.95; P = .017) and 5-year OS rates were 90.1% and 86.4%, respectively (HR, 0.71; 95% CI, 0.53 to 0.94; P = .019). The impact of LA was similar in subgroups defined by menopausal status, tumor size, nodal metastases, and hormone receptor and human epidermal growth factor receptor 2 status. Using competing risk analyses, in LA and no LA arms, 5-year cumulative incidence rates of locoregional recurrence were 3.4% and 4.5% (HR, 0.68; 95% CI, 0.41 to 1.11), and distant recurrence rates were 8.5% and 11.6%, respectively (HR, 0.73; 95% CI, 0.53 to 0.99). There were no adverse events because of lidocaine injection.

CONCLUSION

Peritumoral injection of lidocaine before breast cancer surgery significantly increases DFS and OS. Altering events at the time of surgery can prevent metastases in early breast cancer (CTRI/2014/11/005228).[Media: see text].

Enhanced recovery after surgery in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: national survey of peri-operative practice by Indian society of peritoneal surface malignancies

Objectives

The Enhanced recovery after surgery (ERAS) program is designed to achieve faster recovery by maintaining pre-operative organ function and reducing stress response following surgery. A two part ERAS guidelines specific for Cytoreductive surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) was recently published with intent of extending the benefit to patients with peritoneal surface malignancies. This survey was performed to examine clinicians' knowledge, practice and obstacles about ERAS implementation in patients undergoing CRS and HIPEC.

Methods

Requests to participate in survey of ERAS practices were sent to 238 members of Indian Society of Peritoneal Surface malignancies (ISPSM) via email. They were requested to answer a 37-item questionnaire on elements of preoperative (n=7), intraoperative (n=10) and postoperative (n=11) practices. It also queried demographic information and individual attitudes to ERAS.

Results

Data from 164 respondents were analysed. 27.4 % were aware of the formal ERAS protocol for CRS and HIPEC. 88.4 % of respondents reported implementing ERAS practices for CRS and HIPEC either, completely (20.7 %) or partially (67.7 %). The adherence to the protocol among the respondents were as follows: pre operative (55.5-97.6 %), intra operative (32.6-84.8 %) and post operative (25.6-89 %). While most respondents considered implementation of ERAS for CRS and HIPEC in the present format, 34.1 % felt certain aspects of perioperative practice have potential for improvement. The main barriers to implementation were difficulty in adhering to all elements (65.2 %), insufficient evidence to apply in clinical practice (32.4 %), safety concerns (50.6 %) and administrative issues (47.6 %).

Conclusions

Majority agreed the implementation of ERAS guidelines is beneficial but are followed by HIPEC centres partially. Efforts are required to overcome barriers like improving certain aspects of perioperative practice to increase the adherence, confirming the benefit and safety of protocol with level I evidence and solving administrative issues by setting up dedicated multi-disciplinary ERAS teams.

Use of Indocyanine Green Fluorescence Imaging in Thoracic and Esophageal Surgery

BACKGROUND

Fluorescence imaging using indocyanine green in thoracic and esophageal surgery is gaining popularity because of the potential to facilitate surgical planning, to stage disease, and to reduce postoperative complications. To optimize use of fluorescence imaging in thoracic and esophageal surgery, an expert panel sought to establish a set of recommendations at a consensus meeting.

METHODS

The panel included 12 experts in thoracic and upper gastrointestinal surgery from Asia-Pacific countries. Before meeting, 7 focus areas were defined: intersegmental plane identification for sublobar resections; pulmonary nodule localization; lung tumor detection; bullous lesion detection; lymphatic mapping of lung tumors; evaluation of gastric conduit perfusion; and lymphatic mapping in esophageal surgical procedures. A literature search of the PubMed database was conducted using keywords indocyanine green, fluorescence, thoracic, surgery, and esophagectomy. At the meeting, panelists addressed each focus area by discussing the most relevant evidence and their clinical experiences. Consensus statements were derived from the proceedings, followed by further discussions, revisions, finalization, and unanimous agreement. Each statement was assigned a level of evidence and a grade of recommendation.

RESULTS

A total of 9 consensus recommendations were established. Identification of the intersegmental plane for sublobar resections, localization of pulmonary nodules, lymphatic mapping in lung tumors, and assessment of gastric conduit perfusion were applications of fluorescence imaging that have the most robust current evidence.

CONCLUSIONS

Based on best available evidence and expert opinions, these consensus recommendations may facilitate thoracic and esophageal surgery using fluorescence imaging.

Impact of Covid-19 on gastrointestinal cancer surgery: A National Survey

Purpose

To understand the actual impact of the Covid-19 pandemic and frame the future strategies, we conducted a pan India survey to study the impact on the surgical management of gastrointestinal cancers.

Methods

A national multicentre survey in the form of a questionnaire from 16 tertiary care gastrointestinal oncology centres across India was conducted from January 2019 to June 2021 that was divided into a 15-month pre-Covid era and a similar period of active Covid pandemic era.

Results

There was significant disruption of services; 13 (81%) centres worked as dedicated Covid care centres and 43% reported suspension of essential care for more than 6 months. In active Covid phase, there was a 14.5% decrease in registrations and proportion of decrease was highest in the centres from South zone (22%). There was decrease in resections across all organ systems; maximum reduction was noted in hepatic resections (33%) followed by oesophageal and gastric resections (31 and 25% respectively). There was minimal decrease in colorectal resections (5%). A total of 584 (7.1%) patients had either active Covid-19 infection or developed infection in the post-operative period or had recovered from Covid-19 infection. Only 3 (18%) centres reported higher morbidity, while the rest of the centres reported similar or lower morbidity rates when compared to pre-Covid phase; however, 6 (37%) centres reported slightly higher mortality in the active Covid phase.

Conclusion

Covid-19 pandemic resulted in significant reduction in new cancer registrations and elective gastrointestinal cancer surgeries. Perioperative morbidity remained similar despite 7.1% perioperative Covid 19 exposure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-022-02675-6.

Cytoreductive surgery plus HIPEC for advanced epithelial ovarian cancer: Analysis from a multicentric national Indian HIPEC registry of 1,470 patients—An ISPSM Collaborative study

5525

Background: Improved long-term results can be achieved in advanced epithelial ovarian cancer (EOC) patients using optimal cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Methods: Indian society of peritoneal surface malignancy (ISPSM) is a registered body which maintains prospective data of 26 centers across India who perform CRS –HIPEC. From February 2017 until January 2022, 1470 patients with advanced EOC were treated with CRS-HIPEC. He general practice patterns and the oncological outcomes in terms of progression free survival (PFS) and overall survival (OS) & post-operative morbidity and mortality is reported. Results: Upfront (n = 156), interval (n = 645) and recurrent (n = 669) cytoreductions were performed based on the timeline at presentation. Mean age 54.5±10.74, PCI 13. 6±5.2, duration of surgery 10.6±1.h hrs. 36.4% had total peritonectomy, 12.7% had multivisceral resection, 41.8%had bowel resections and stoma rate was 7.4%. 60.3% had semiopen HIPEC, 83.1% used cisplatin for HIPEC and 83.1 % had HIPEC for 90 minutes. Overall G3-G5 morbidity was 25.4% with major ones being post-operative intra-abdominal collection (21.8%), electrolyte imbalance (16.4%), pulmonary (16.4%) followed by hematological (12.7%). Surgical morbidity was more in upfront cytoreduction group compared to interval group (20% versus 13.5%) and recurrent group (20% versus 15%), respectively. The 30 day mortality was 3.8%. With a median follow-up of 46 months, median PFS was 33 months in primary (upfront plus interval) group and 16 months in recurrent cytoreduction group. Median OS was not achieved in both primary and recurrent groups (4 year OS rates: 60 and 55%, respectively). Conclusions: This prospective database provides a collation and audit of the management of advanced epithelial ovarian cancer with CRS HIPEC in multiple centers registered under ISPSM. In advanced EOC patients, CRS plus HIPEC offers potential benefits in PFS and OS rates, with acceptable rates of morbidity and mortality and can be practiced even in resource constrained setting.

Fluorescence-guided cancer surgery-A new paradigm

Fluorescence-guided surgery is an emerging and promising operative adjunct to assist the surgeon in various aspects of oncosurgery, ranging from assessing perfusion, identification, and characterization of tumors and peritoneal metastases, mapping of lymph nodes/leaks, and assistance for fluorescence-guided surgery (FGS). This study aims to provide an overview of principles, currently available dyes, platforms, and surgical applications and summarizes the available literature on the utility of FGS with a focus on abdomino-thoracic malignancies.

Minimal Invasive Esophagectomy-a New Dawn of EsophagealSurgery

Surgery is the mainstay of esophageal cancer. However, esophagectomy is a major surgical trauma on a patient with high morbidity and mortality. The intent of minimally invasive esophagectomy (MIE) is to decrease the degree of surgical trauma and perioperative morbidity associated with open surgery, and provide faster recovery and shorter hospital stay with the equivalent oncological outcome. It also allows for lesser pulmonary morbidity, less blood loss, less pain, and a better quality of life. MIE is safe and effective but has a steep learning curve with high technical expertise. Recently, it is increasingly accepted and adopted all over the globe. In this article, we discuss the safety, efficacy, short-term, and oncological outcomes of thoracoscopic- and laparoscopic-assisted minimally invasive esophagectomy and robotic surgery compared with open esophagectomy with a special focus on the Indian perspective.

Flickering diaphragm sign, an indicator of laparoscopy-associated pneumothorax secondary to pleural breach

During laparoscopic mobilisation of the oesophagus around hiatus in transhiatal oesophagectomy; commonly the pleura is breached causing iatrogenic pneumothorax. Often small breaches in pleura goes unnoticed till the attention is drawn by anaesthetist when pressures drop with building up of end-tidal CO₂(etCO2) and other haemodynamic changes occur. We describe the flickering movements of the diaphragm associated with the pleural breach, a useful sign to alert the surgeon and anaesthetist to detect pneumothorax earlier than it is clinically evident.

Short-term Outcomes in Patients with Carcinoma of the Esophagus and Gastroesophageal Junction Receiving Neoadjuvant Chemotherapy or Chemoradiation before Surgery. A Prospective Study

BACKGROUND

Neoadjuvant chemotherapy (NACT) and neoadjuvant chemoradiotherapy (NACRT) have been demonstrated to improve survival compared to surgery alone in esophageal carcinoma, but the evidence is scarce on which of these therapies is more beneficial, particularly with regard to resectability rates, postoperative morbidity and mortality, and histological responses.

OBJECTIVE

This study compares the resectability, pathological response rates, and short-term surgical outcomes in patients with carcinoma of the esophagus or gastroesophageal junction receiving NACT or NACRT prior to surgery.

METHODS

Patients with resectable carcinoma of the esophagus or gastroesophageal junction adenocarcinoma, squamous cell carcinoma, and adenosquamous histologies were enrolled in this well-matched prospective non-randomized study. Thirty-five patients were given NACT, and 35 NACRT. In the NACT group, 25 patients received three cycles of three-weekly carboplatin and paclitaxel, and 10 received three cycles of cisplatin/5-fluorouracil, while all the patients in the NACRT group received 41.4 Gy of radiotherapy concomitant with five cycles of weekly paclitaxel and carboplatin-based chemotherapy.

RESULTS

Twenty-two patients in the NACT group and 33 patients in NACRT group had resection (P value = 0.0027). The percentage of microscopically margin-negative resection (R0 resection) was similar in both the groups (86% versus 88%). The incidences of surgical and non-surgical complications were similar in both the groups (P=0.34). There was no 30-day mortality. There was a trend toward more pathological complete regression in the NACRT group (P=0.067). The percentage of patients achieving complete tumor regression at the primary site (pT0) was significantly higher in the NACRT group. The down-staging effect on nodal status was similar in both the groups (P=0.55). There was a statistically significant reduction in tumor size in the NACRT group. The median numbers of nodes harvested and positive nodes were similar in both the groups.

CONCLUSION

Patients receiving NACRT had better resectability rates and pathological response rates, but similar postoperative morbidity compared to the NACT group.

Uterine Sarcomas: Experience from a Tertiary Cancer Care Center from India

Uterine sarcomas are uncommon and aggressive tumors comprising 3-7% of all uterine malignancies. The aim is to evaluate clinical presentation, histopathologic pattern, recurrence pattern, and outcome of patients with uterine sarcomas presenting to a tertiary care cancer center over an 8-year period. A total of 11 cases of uterine sarcoma were diagnosed. The median age of patients at presentation was 51 years (range 30-67 years). Six patients had leiomyosarcoma (54.5%), 4 had endometrial stromal sarcoma (36%), and 1 had adenosarcoma (9%). The main presenting symptoms were abnormal vaginal bleeding, low abdominal pain, and white discharge. Median follow-up was 11 months ranging from 3 to 200 months. Median survivals for leiomyosarcoma, endometrial stromal sarcoma, and adenosarcoma were 6.5, 18, and 56 months. The 3- and 5-year survival by Kaplan-Meier survival analysis of the entire cohort was 30 and 20%. The mitotic index, age, adjuvant therapy (chemotherapy, radiotherapy), and performance of pelvic nodal dissection did not impact survival significantly in the patient with leiomyosarcoma. Stage and histology had the strongest bearing on survival and leiomyosarcoma has the worst survival, whereas adenosarcoma had the best prognosis. Adequately powered prospective studies are required to define the role of radiation therapy and chemotherapy in this rare disease.

Abstract 3766: Low frequency of MLH1/MSH2 inactivation in suspected HNPCC patients from India

Hereditary Non-Polyposis Colorectal Cancer (HNPCC) is an autosomal dominant familial syndrome resulting in colorectal cancer at a young age. It is caused mainly due to germline mutational inactivation of any one of four mismatch repair (MMR) genes viz. MSH2, MLH1, MSH6 and PMS2 resulting in the ‘mutator’ phenotype called microsatellite instability (MSI). The mutations often result in loss of protein expression which can be detected using immunohistochemistry (IHC). IHC and MSI analysis have been suggested as pre-screening methods for selection of patients for mutation analysis of MMR genes. Studies from several populations have indicated that MLH1/MSH2 inactivation may account for a majority of HNPCC cases. We earlier reported unique clinico-pathological and molecular genetic features in Indian sporadic colorectal cancer patients. We have now carried out a multi pronged analysis of suspected HNPCC patients from India. MSI screening and IHC for MLH1 and MSH2 followed by mutation analysis was employed on a panel of Indian CRC patients who were aged below 50 years at the time of diagnosis and exhibited HNPCC-specific family history. We also included patients who had multiple primary tumors or were of older age but exhibited HNPCC-specific familial involvement. As expected, a significant majority of patients (upto 80%) harbored tumors exhibiting high MSI (MSI-H) as compared to young patients without family history (only upto 20%). Surprisingly, a significantly low proportion (only about 30%) of young patients positive for family history and MSI-H exhibited loss of MLH1/MSH2 expression, perhaps due to mutations not resulting in loss of protein expression or the involvement of MSH6/PMS2 in Indian patients at a frequency higher than other populations. IHC for MSH6/PMS2 is currently underway. Mutation screening for the appropriate gene was carried out in eight patients negative for IHC using genomic DNA isolated from blood samples. Six heterozygous germline mutations (including four novel mutations) were identified; three each in MLH1 and MSH2. Studies are ongoing to determine whether the second allele in each of the six cases was inactivated through loss of heterozygosity. Interestingly, all patients in whom mutation was identified harbored tumor in the ascending colon. Three of the six mutations generate premature termination codons expected to trigger nonsense mediated decay resulting in reduced transcript levels of the respective genes. A fourth mutation (in MLH1) resulted in drastic reduction in transcript levels as determined by quantitative reverse transcription polymerase chain reaction; no such reduction was discernable in a microsatellite stable sporadic CRC sample. Analysis of effect of the remaining two mutations is currently underway. Our results therefore reveal unique features in Indian HNPCC patients; IHC for MLH1/MSH2 may not be an ideal primary screening tool to identify HNPCC patients in India.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3766. doi:10.1158/1538-7445.AM2011-3766