Role of neoadjuvant therapy(chemotherapy and/or radiotherapy) in lymph node and primary rectal tumor regression and prognosis (Preprint)

UNSTRUCTURED Background: Rectal tumors are important malignancies and prediction of prognosis after neoadjuvant therapy is important to improve the prognosis process. The purpose of this study was to determine therole ofneoadjuvant therapy in lymph node regression and primary rectal tumor as well as its association with prognosis. Methods and materials: In this descriptive study, 40 consecutive patients with rectal tumor who were referred toTaleghani Hospital for surgery from 2011 to 2018 were enrolled. Moreover, theneoadjuvant therapy role in lymph node regression and primary rectal tumor was determined as well as its association with prognosis. Results: The results of this study demonstrate that there was no tumor regression in 20% of patients and it wasalso less than 25%, 25-50%, 50-75%, and complete in 22.5%, 35%, 20%, and 2.5% of the patients,respectively. The lymph node regression was complete in 5% of the patients and it wasalso less than 25% in 20% and more than 25% in 50% of them. In addition, it was with no regression in 25% of the patients. The lymph node regression was related to N stage (P=0.018), primary tumor regression grade (P=0.001), yPT (P=0.008), and yPN (P=0.020); however, it was not related to prognosis (P > 0.05). Conclusions: Totally, according to the obtained results, it can be concluded thatneoadjuvant therapy plays a good role in lymph node regression and primary rectal tumor, but it has no association with prognosis. Keywords:Neoadjuvant therapy, Lymph node regression, Primary rectal tumor, Prognosis

Overexpression of MLPH in Rectal Cancer Patients Correlates with a Poorer Response to Preoperative Chemoradiotherapy and Reduced Patient Survival

Data mining of a public transcriptomic rectal cancer dataset (GSE35452) from the Gene Expression Omnibus, National Center for Biotechnology Information identified the melanophilin (MLPH) gene as the most significant intracellular protein transport-related gene (GO:0006886) associated with a poor response to preoperative chemoradiation. An MLPH immunostain was performed on biopsy specimens from 172 rectal cancer patients receiving preoperative chemoradiation; samples were divided into high- and low-expression groups by H-scores. Subsequently, the correlations between MLPH expression and clinicopathologic features, tumor regression grade, disease-specific survival (DSS), local recurrence-free survival (LRFS), and metastasis-free survival (MeFS) were analyzed. MLPH expression was significantly associated with CEA level (p = 0.001), pre-treatment tumor status (p = 0.022), post-treatment tumor status (p < 0.001), post-treatment nodal status (p < 0.001), vascular invasion (p = 0.028), and tumor regression grade (p < 0.001). After uni- and multi-variable analysis of five-year survival, MLPH expression was still associated with lower DSS (hazard ratio (HR), 10.110; 95% confidence interval (CI), 2.178–46.920; p = 0.003) and MeFS (HR, 5.621; 95% CI, 1.762–17.931; p = 0.004). In conclusion, identifying MLPH expression could help to predict the response to chemoradiation and survival, and aid in personal therapeutic modification.

ROLE OF COMPUTED TOMOGRAPHY WITH PNEUMOGASTROGRAPHY IN DETERMINING THE REGRESSION GRADE OF LOCALLY ADVANCED GASTRIC CANCER AFTER NEOADJUVANT CHEMOTHERAPY

Introduction. A multimodal approach to the treatment of locally advanced gastric cancer with the addition of systemic or local treatment methods, such as chemotherapy and radiation therapy, reduces the risk of cancer recurrence, thus improving survival of patients. Advances in anticancer therapy dictate the need to develop systems for assessing tumor response to new treatment modalities.Material and Methods. The study included 162 patients with locally advanced gastric cancer who received treatment at the N.N. Petrov National Medical Research Center of Oncology from 2015 to 2018. All patients underwent subtotal gastric resection or gastrectomy with lymph node dissection and previously received neoadjuvant polychemotherapy. Patients were in the age range 30 to 80 years old. The tumor pathomorphological response to chemotherapy was assessed in all patients using a pathomorphological response rate system according to the classification of the Japanese Gastric Cancer Association (JGCA, 3rd English edition). All patients underwent computed tomography with pneumogastrography before neoadjuvant chemotherapy and immediately before surgery. For each of 162 patients, 96 qualitative and quantitative biomarkers of tumor and paragastric lymph node imaging were analyzed.Results. The accuracy of determining the tumor response rate using computed tomography with pneumogastrography was 82.6 % for TRG-0/1, 90 % for TRG-1/2, and 88 % for TRG-2/3. Discussion. The tumor pathomorphological response to treatment is a predictor of long-term results; however, it can be assessed only after analyzing the surgical specimen, and this marker cannot be used in inoperable cases and for correction of palliative chemotherapy. The study of imaging biomarkers based on quantitative and qualitative data reflecting the histopathological features of the tumor and lymph nodes can help determine the tumor regression grade and optimize treatment.Conclusion. The proposed algorithm for assessing the response grade of locally advanced gastric cancer to chemotherapy using imaging biomarkers is a promising prognostic marker and requires further study.

Neoadjuvant Therapy of Metformin is Associated with Good Tumor Response After Preoperative Concurrent Chemoradiotherapy for Rectal Cancer

Metformin is associated with good tumor response in preoperative concurrent chemoradiotherapy (CCRT) for rectal cancer. This study aims to demonstrate that the timing of metformin is related to the tumor response on preoperative CCRT for rectal cancer. From January 2010 to December 2017, 232 patients who underwent curative resection after preoperative CCRT were reviewed. Patients were divided into groups with or without diabetes or metformin. The timing of metformin administration was divided based on before and after initiation of chemoradiotherapy. Multivariate logistic regression analysis was used to identify predictors for tumor response. Tumor downstaging (p = 0.02) and good response rates of tumor regression grade (TRG) (p = 0.008) were significantly higher in the group administered metformin before CCRT than other groups. In the multivariate analysis, metformin administration before CCRT was a significant factor in predicting tumor downstaging (odds ratio [OR] 10.31, 95% confidence interval [CI]: 1.76 - 102.08, p = 0.02) and good TRG (OR 12.55, 95% CI: 2.38 - 80.24, p = 0.004). In patients with rectal cancer who underwent preoperative CCRT, neoadjuvant therapy of metformin before CCRT was significantly associated with good tumor response and tumor downstaging.

Significance of chemotherapy-free interval and tumor regression grade in patients with recurrent esophageal squamous cell carcinoma receiving chemotherapy with fluorouracil and platinum after esophagectomy following preoperative chemotherapy

Background In Japan, standard treatment for locally advanced esophageal squamous cell carcinoma (ESCC) includes preoperative chemotherapy with fluorouracil plus cisplatin followed by esophagectomy. However, its efficacy is unclear in patients with recurrent disease with < 6 months of chemotherapy-free interval (CFI) after preoperative chemotherapy followed by esophagectomy and in those with ≥ 6 months of CFI and poor pathological response to prior preoperative chemotherapy. Method We retrospectively evaluated the efficacy of fluorouracil plus platinum in patients with recurrent ESCC who received preoperative chemotherapy followed by curative esophagectomy. Results Among 105 patients with recurrent ESCC after preoperative chemotherapy followed by esophagectomy, a total of 55 patients received fluorouracil plus platinum for recurrent disease. Patients with a CFI < 6 months (n = 20) had significantly shorter overall survival (OS) (median, 7.1 vs 14.5 months, P = 0.008) compared with those with a CFI ≥ 6 months (n = 35). Multivariate analysis showed that OS was worse in patients with a CFI < 6 months or a tumor regression grade (TRG) ≤ 1a. Furthermore, in patients with a CFI ≥ 6 months, TRG ≤ 1a was associated with significantly shorter OS (11.1 months vs. not reached, P = 0.001). Conclusion Fluorouracil plus platinum was ineffective for recurrent ESCC in patients with a CFI < 6 months and in those with a CFI ≥ 6 months and a TRG ≤ 1a. Alternate regimens including nivolumab or pembrolizumab might be considered for the treatment for recurrence in these patients.

Naples Prognostic Score Predicts Tumor Regression Grade in Resectable Gastric Cancer Treated with Preoperative Chemotherapy

Despite recent progresses, locally advanced gastric cancer remains a daunting challenge to embrace. Perioperative chemotherapy and D2-gastrectomy depict multimodal treatment of gastric cancer in Europe, shows better results than curative surgery alone in terms of downstaging, micrometastases elimination, and improved long-term survival. Unfortunately, preoperative chemotherapy is useless in about 50% of cases of non-responder patients, in which no effect is registered. Tumor regression grade (TRG) is directly related to chemotherapy effectiveness, but its understanding is achieved only after surgical operation; accordingly, preoperative chemotherapy is given indiscriminately. Conversely, Naples Prognostic Score (NPS), related to patient immune-nutritional status and easily obtained before taking any therapeutic decision, appeared an independent prognostic variable of TRG. NPS was calculated in 59 consecutive surgically treated gastric cancer patients after neoadjuvant FLOT4-based chemotherapy. 42.2% of positive responses were observed: all normal NPS and half mild/moderate NPS showed significant responses to chemotherapy with TRG 1–3; while only 20% of the worst NPS showed some related benefits. Evaluation of NPS in gastric cancer patients undergoing multimodal treatment may be useful both in selecting patients who will benefit from preoperative chemotherapy and for changing immune-nutritional conditions in order to improve patient’s reaction against the tumor.

Utility of ctDNA in predicting response to neoadjuvant chemoradiotherapy and prognosis assessment in locally advanced rectal cancer: A prospective cohort study

Background For locally advanced rectal cancer (LARC) patients who receive neoadjuvant chemoradiotherapy (nCRT), there are no reliable indicators to accurately predict pathological complete response (pCR) before surgery. For patients with clinical complete response (cCR), a “Watch and Wait” (W&W) approach can be adopted to improve quality of life. However, W&W approach may increase the recurrence risk in patients who are judged to be cCR but have minimal residual disease (MRD). Magnetic resonance imaging (MRI) is a major tool to evaluate response to nCRT; however, its ability to predict pCR needs to be improved. In this prospective cohort study, we explored the value of circulating tumor DNA (ctDNA) in combination with MRI in the prediction of pCR before surgery and investigated the utility of ctDNA in risk stratification and prognostic prediction for patients undergoing nCRT and total mesorectal excision (TME). Methods and findings We recruited 119 Chinese LARC patients (cT3-4/N0-2/M0; median age of 57; 85 males) who were treated with nCRT plus TME at Fudan University Shanghai Cancer Center (China) from February 7, 2016 to October 31, 2017. Plasma samples at baseline, during nCRT, and after surgery were collected. A total of 531 plasma samples were collected and subjected to deep targeted panel sequencing of 422 cancer-related genes. The association among ctDNA status, treatment response, and prognosis was analyzed. The performance of ctDNA alone, MRI alone, and combining ctDNA with MRI was evaluated for their ability to predict pCR/non-pCR. Ranging from complete tumor regression (pathological tumor regression grade 0; pTRG0) to poor regression (pTRG3), the ctDNA clearance rate during nCRT showed a significant decreasing trend (95.7%, 77.8%, 71.1%, and 66.7% in pTRG 0, 1, 2, and 3 groups, respectively, P = 0.008), while the detection rate of acquired mutations in ctDNA showed an increasing trend (3.8%, 8.3%, 19.2%, and 23.1% in pTRG 0, 1, 2, and 3 groups, respectively, P = 0.02). Univariable logistic regression showed that ctDNA clearance was associated with a low probability of non-pCR (odds ratio = 0.11, 95% confidence interval [95% CI] = 0.01 to 0.6, P = 0.04). A risk score predictive model, which incorporated both ctDNA (i.e., features of baseline ctDNA, ctDNA clearance, and acquired mutation status) and MRI tumor regression grade (mrTRG), was developed and demonstrated improved performance in predicting pCR/non-pCR (area under the curve [AUC] = 0.886, 95% CI = 0.810 to 0.962) compared with models derived from only ctDNA (AUC = 0.818, 95% CI = 0.725 to 0.912) or only mrTRG (AUC = 0.729, 95% CI = 0.641 to 0.816). The detection of potential colorectal cancer (CRC) driver genes in ctDNA after nCRT indicated a significantly worse recurrence-free survival (RFS) (hazard ratio [HR] = 9.29, 95% CI = 3.74 to 23.10, P < 0.001). Patients with detectable driver mutations and positive high-risk feature (HR_feature) after surgery had the highest recurrence risk (HR = 90.29, 95% CI = 17.01 to 479.26, P < 0.001). Limitations include relatively small sample size, lack of independent external validation, no serial ctDNA testing after surgery, and a relatively short follow-up period. Conclusions The model combining ctDNA and MRI improved the predictive performance compared with the models derived from individual information, and combining ctDNA with HR_feature can stratify patients with a high risk of recurrence. Therefore, ctDNA can supplement MRI to better predict nCRT response, and it could potentially help patient selection for nonoperative management and guide the treatment strategy for those with different recurrence risks.

Temporal determinants of tumour response to neoadjuvant rectal radiotherapy

Introduction In locally advanced rectal cancer, longer delay to surgery after neoadjuvant radiotherapy increases the likelihood of histopathological tumour response. Chronomodulated radiotherapy in rectal cancer has recently been reported as a factor increasing tumour response to neoadjuvant treatment in patients having earlier surgery, with patients receiving a larger proportion of afternoon treatments showing improved response. This paper aims to replicate this work by exploring the impact of these two temporal factors, independently and in combination, on histopathological tumour response in rectal cancer patients. Methods A retrospective review of all patients with rectal adenocarcinoma who received long course (≥24 fractions) neoadjuvant radiotherapy with or without chemotherapy at a tertiary referral centre was conducted. Delay to surgery and radiotherapy treatment time were correlated to clinicopathologic characteristics with a particular focus on tumour regression grade. A review of the literature and meta-analysis were also conducted to ascertain the impact of time to surgery from preoperative radiotherapy on tumour regression. Results From a cohort of 367 patients, 197 patients met the inclusion criteria. Complete pathologic response (AJCC regression grade 0) was seen in 46 (23%) patients with a further 44 patients (22%) having at most small groups of residual cells (AJCC regression grade 1). Median time to surgery was 63 days, and no statistically significant difference was seen in tumour regression between patients having early or late surgery. There was a non-significant trend towards a larger proportion of morning treatments in patients with grade 0 or 1 regression (p = 0.077). There was no difference in tumour regression when composite groups of the two temporal variables were analysed. Visualisation of data from 39 reviewed papers (describing 27379 patients) demonstrated a plateau of response to neoadjuvant radiotherapy after approximately 60 days, and a meta-analysis found improved complete pathologic response in patients having later surgery. Conclusions There was no observed benefit of chronomodulated radiotherapy in our cohort of rectal cancer patients. Review of the literature and meta-analysis confirms the benefit of delayed surgery, with a plateau in complete response rates at approximately 60-days between completion of radiotherapy and surgery. In our cohort, time to surgery for the majority of our patients lay along this plateau and this may be a more dominant factor in determining response to neoadjuvant therapy, obscuring any effects of chronomodulation on tumour response. We would recommend surgery be performed between 8 and 11 weeks after completion of neoadjuvant radiotherapy in patients with locally advanced rectal cancer.

Prognostic implications of regression of metastatic axillary lymph nodes after neoadjuvant chemotherapy in patients with breast cancer

Prognostic implications of therapeutic response of metastatic lymph nodes (LNs) to neoadjuvant chemotherapy (NAC) remain unclear in patients with breast cancer. We aimed to evaluate the prognostic value of axillary LN regression after NAC in locally-advanced breast cancer patients. Therapeutic response of the LNs was evaluated in 563 breast cancer patients and classified into four grades according to the regression pattern. Initial pathologic N stage was estimated from the sum of the metastatic LNs and those with complete regression. In survival analyses, LN regression grade, pathologic N stage after NAC, and presumed initial pathologic N stage stratified clinical outcome of the patients in the whole group, in both ER-positive and ER-negative subgroups, and in those with residual breast disease. On multivariate analysis, LN regression grade and presumed initial pathologic N stage were revealed as independent prognostic factors. The number of completely-responsive LNs and the ratio of non-responsive LNs also revealed a prognostic value. In conclusion, regression grade of axillary LNs and presumed initial pathologic N stage have prognostic values in breast cancer patients who receive NAC. Thus, regression of axillary LNs should be evaluated and included in pathologic reporting of post-NAC resection specimens.