Tumour-stroma ratio to predict pathological response to neo-adjuvant treatment in rectal cancer.

INTRODUCTION: Management of rectal cancer has advanced, with an increasing use of neoadjuvant chemoradiotherapy (nCRT). This opens options for organ preserving treatment for those with a major response to nCRT. However, the degree of clinical response, based on MRI and post-treatment biopsies, only poorly matches the degree of actual pathological response. In order to select patients with major pathological response without surgical resection, it is of importance to define tumour markers predicting the degree of pathological response to nCRT. The intra-tumoural tumour-stroma ratio (TSR) might be this marker. METHODS: TSR in pre-treatment biopsies was estimated according to the method described by van Pelt et al. The degree of pathological response was assessed on the tumour resection according to tumour regression grading (TRG) by Mandard. The primary endpoint of this study was the difference in pathological response to nCRT between TSR-high and TSR-low groups. RESULTS: We found that 26.2% of patients with major response was classified as TSR-high, while 73.8% of patients were classified as TSR-low. A high TSR in pre-treatment biopsies was associated with a lower chance of major-response to nCRT (OR = 0.37, 95%CI; 0.19-0.73), p = 0.004), independent of tumour stage and time between nCRT and surgery. CONCLUSION: In rectal cancer, TSR in pre-treatment biopsies predicts pathologic response to nCRT, with a high TSR bringing twice the risk of poor to no response compared to low TSR. In future, assessment of TSR may fulfil a role in a therapeutic algorithm identifying patients who will or will not respond to nCRT prior to treatment initiation.

A high tumour-stroma ratio (TSR) in colon tumours and its metastatic lymph nodes predicts poor cancer-free survival and chemo resistance.

PURPOSE: Despite known high-risk features, accurate identification of patients at high risk of cancer recurrence in colon cancer remains a challenge. As tumour stroma plays an important role in tumour invasion and metastasis, the easy, low-cost and highly reproducible tumour-stroma ratio (TSR) could be a valuable prognostic marker, which is also believed to predict chemo resistance. METHODS: Two independent series of patients with colon cancer were selected. TSR was estimated by microscopic analysis of 4 µm haematoxylin and eosin (H&E) stained tissue sections of the primary tumour and the corresponding metastatic lymph nodes. Patients were categorized as TSR-low (≤ 50%) or TSR-high (> 50%). Differences in overall survival and cancer-free survival were analysed by Kaplan-Meier curves and cox-regression analyses. Analyses were conducted for TNM-stage I-II, TNM-stage III and patients with an indication for chemotherapy separately. RESULTS: We found that high TSR was associated with poor cancer-free survival in TNM-stage I-II colon cancer in two independent series, independent of other known high-risk features. This association was also found in TNM-stage III tumours, with an additional prognostic value of TSR in lymph node metastasis to TSR in the primary tumour alone. In addition, high TSR was found to predict chemo resistance in patients receiving adjuvant chemotherapy after surgical resection of a TNM-stage II-III colon tumour. CONCLUSION: In colon cancer, the TSR of both primary tumour and lymph node metastasis adds significant prognostic value to current pathologic and clinical features used for the identification of patients at high risk of cancer recurrence, and also predicts chemo resistance.

Is pre-operative heart rate variability a prognostic indicator for overall survival and cancer recurrence in patients with primary colorectal cancer?

BACKGROUND: Heart Rate Variability (HRV) represents efferent vagus nerve activity which is suggested to be inversely related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various types of cancer. HRV is also believed to predict the occurrence and severity of post-operative complications. We aimed to determine the role of pre-operative HRV as a prognostic factor in overall and cancer free survival in patients with colorectal cancer. METHODS: Retrospective analysis was performed in a detailed dataset of patients diagnosed with primary colorectal cancer between January 2010 and December 2016, who underwent curative surgical treatment. HRV was measured as time-domain parameters (SDNN (Standard Deviation of NN-intervals) and RMSSD (Root Mean Square of Successive Differences)) based on pre-operative 10 second ECGs. Groups were created by baseline HRV: Low HRV (SDNN <20ms or RMSSD <19ms) and normal HRV (SDNN ≥20ms or RMSSD ≥19ms). Primary endpoints were overall and cancer free survival. RESULTS: A total of 428 patients were included in this study. HRV was not significantly associated with overall survival (SDNN <20ms vs SDNN ≥20ms:24.4% vs 22.8%, adjusted HR = 0.952 (0.607-1.493), p = 0.829; RMSSD <19ms vs RMSSD ≥19ms:27.0% vs 19.5%, adjusted HR = 1.321 (0.802-2.178), p = 0.274) or cancer recurrence (SDNN <20ms vs ≥20ms:20.1% vs 18.7%, adjusted HR = 0.976 (0.599-1.592), p = 0.924; RMSSD <19ms vs ≥19ms, 21.5% vs 16.9%, adjusted HR = 1.192 (0.706-2.011), p = 0.511). There was no significant association between HRV and CEA-level at one year follow-up, or between HRV and occurrence of a post-operative complication or the severity of post-operative complications. CONCLUSIONS: Heart rate variability was not associated with overall or cancer free survival in patients with primary colorectal cancer who underwent curative surgical treatment. These results do not align with results found in studies including only patients with advanced cancer, which suggests that there is only an association in the other direction, cancer causing low HRV.