Rapid Reduction of CEA and Stable Metastasis in an NRAS-mutant Rectal-Cancer Patient Treated With FOLFIRI and Bevacizumab Combined With Oral Recombinant Methioninase and a Low-Methionine Diet Upon Metastatic Recurrence After FOLFIRI and Bevacizumab Treatment Alone.

BACKGROUND/AIM: The choice of chemotherapy agents for RAS-mutant colorectal cancer is limited, and prognosis is poor compared to RAS-wild-type colorectal cancer. The purpose of the present study was to evaluate the effectiveness of methionine restriction combined with chemotherapy in a patient with NRAS-mutant rectal cancer. PATIENTS AND METHODS: A 59-year-old female was diagnosed with lung-metastatic recurrence of NRAS-mutant rectal cancer two and a half years after resection of the primary tumor. She started chemotherapy, which consisted of fluorouracil, irinotecan (FOLFIRI), and bevacizumab, in October 2020. Eight months later, stereotactic body radiation therapy (SBRT) was performed to treat the lung metastases. She stopped chemotherapy at this point and had blood tests and computed tomography (CT) scans regularly. Her CEA level increased to 139.91 ng/ml and her lung metastasis became larger by September 2022. Therefore, she was reintroduced to FOLFIRI and bevacizumab in October 2022, and also started a low-methionine diet and oral recombinant methioninase (o-rMETase) as a supplement. RESULTS: After starting the combination therapy with o-rMETase, a low-methionine diet, FOLFIRI, and bevacizumab, blood CEA levels very rapidly decreased and were almost within the normal limits five months later. CT findings showed the lung metastasis did not grow. CONCLUSION: Methionine restriction comprising o-rMETase and a low-methionine diet combined with first-line chemotherapy was effective in a patient with NRAS-mutant rectal cancer in which metastasis had re-occurred after first-line chemotherapy alone.

An integrated multiomics analysis of rectal cancer patients identified POU2F3 as a putative druggable target and entinostat as a cytotoxic enhancer of 5-fluorouracil.

Rectal cancer (RC) accounts for one-third of colorectal cancers (CRC), and 40% of these are locally advanced rectal cancers (LARC). The use of neoadjuvant chemoradiotherapy (nCRT) significantly reduces the rate of local recurrence compared to adjuvant therapy or surgery alone. However, after nCRT, up to 40%-60% of patients show a poor pathological response, while only about 20% achieve a pathological complete response. In this scenario, the identification of novel predictors of tumor response to nCRT is urgently needed to reduce LARC mortality and to spare poorly responding patients from unnecessary treatments. Therefore, by combining gene and microRNA expression datasets with proteomic data from LARC patients, we developed an integrated network centered on seven hub-genes putatively involved in the response to nCRT. In an independent validation cohort of LARC patients, we confirmed that differential expression of NFKB1, TRAF6 and STAT3 is correlated with the response to nCRT. In addition, the functional enrichment analysis also revealed that these genes are strongly related to hallmarks of cancer and inflammation, whose dysfunction may causatively affect LARC patient's response to nCRT. Furthermore, by constructing the transcription factor-module network, we hypothesized a protective role of POU2F3 gene, which could be used as a new drug target in LARC patients. Finally, we identified and tested in vitro entinostat, a histone deacetylase inhibitor, as a chemical compound that could be combined with a classical therapeutic regimen in order to design more efficient therapeutic strategies in LARC management.

Transcriptomic Analyses of Pretreatment Tumor Biopsy Samples, Response to Neoadjuvant Chemoradiotherapy, and Survival in Patients With Advanced Rectal Cancer.

Importance: Neoadjuvant chemoradiotherapy (CRT) is the standard of care for advanced rectal cancer. Yet, estimating response to CRT remains an unmet clinical challenge. Objective: To investigate and better understand the transcriptomic factors associated with response to neoadjuvant CRT and survival in patients with advanced rectal cancer. Design, Setting, and Participants: A single-center, retrospective, case series was conducted at a comprehensive cancer center. Pretreatment biopsies from 298 patients with rectal cancer who were later treated with neoadjuvant CRT between April 1, 2004, and September 30, 2020, were analyzed by RNA sequencing. Data analysis was performed from July 1, 2021, to May 31, 2022. Exposures: Chemoradiotherapy followed by total mesorectal excision or watch-and-wait management. Main Outcomes and Measures: Transcriptional subtyping was performed by consensus molecular subtype (CMS) classification. Immune cell infiltration was assessed using microenvironment cell populations-counter (MCP-counter) scores and single-sample gene set enrichment analysis (ssGSEA). Patients with surgical specimens of tumor regression grade 3 to 4 or whose care was managed by the watch-and-wait approach for more than 3 years were defined as good responders. Results: Of the 298 patients in the study, 205 patients (68.8%) were men, and the median age was 61 (IQR, 52-67) years. Patients classified as CMS1 (6.4%) had a significantly higher rate of good response, albeit survival was comparable among the 4 subtypes. Good responders exhibited an enrichment in various immune-related pathways, as determined by ssGSEA. Microenvironment cell populations-counter scores for cytotoxic lymphocytes were significantly higher for good responders than nonresponders (median, 0.76 [IQR, 0.53-1.01] vs 0.58 [IQR, 0.43-0.83]; P < .001). Cytotoxic lymphocyte MCP-counter score was independently associated with response to CRT, as determined in the multivariable analysis (odds ratio, 3.81; 95% CI, 1.82-7.97; P < .001). Multivariable Cox proportional hazards regression analysis, including postoperative pathologic factors, revealed the cytotoxic lymphocyte MCP-counter score to be independently associated with recurrence-free survival (hazard ratio [HR], 0.38; 95% CI, 0.16-0.92; P = .03) and overall survival (HR, 0.16; 95% CI, 0.03-0.83; P = .03). Conclusions and Relevance: In this case series of patients with rectal cancer treated with neoadjuvant CRT, the cytotoxic lymphocyte score in pretreatment biopsy samples, as computed by RNA sequencing, was associated with response to CRT and survival. This finding suggests that the cytotoxic lymphocyte score might serve as a biomarker in personalized multimodal rectal cancer treatment.

Protocol of the QUATTRO-II study: a multicenter randomized phase II study comparing CAPOXIRI plus bevacizumab with FOLFOXIRI plus bevacizumab as a first-line treatment in patients with metastatic colorectal cancer.

BACKGROUND: First-line treatment with FOLFOXIRI plus bevacizumab (BEV) is highly effective and regarded as one of the standards-of-care for patients with metastatic colorectal cancer (mCRC), despite the high incidence of neutropenia and diarrhea as side effects. AXEPT, an Asian phase III study, showed that modified CAPIRI+BEV [capecitabine (CAP: 1600 mg/m2), irinotecan (IRI: 200 mg/m2), and BEV (7.5 mg/m2)] was non-inferior to FOLFIRI+BEV as a second-line therapy for mCRC patients and was associated with a lower incidence of hematologic toxicities. Thus, a reduced dose of the CAP and IRI regimen in combination with oxaliplatin (OX) and BEV (CAPOXIRI+BEV) may be more feasible than FOLFOXIRI+BEV, without compromising efficacy. METHODS: QUATTRO-II is an open-label, multicenter, randomized phase II study. In Step 1, the recommended doses of OX and IRI will be investigated as a safety lead-in. In Step 2, patients will be randomized to the recommended dose of either CAPOXIRI+BEV or FOLFOXIRI+BEV. Induction triplet chemotherapy plus BEV treatments will be administered for up to 4 months followed by fluoropyrimidine plus BEV maintenance. The primary endpoint is progression-free survival (PFS). The similarity in PFS between the two arms will be evaluated by observing whether the point estimate of hazard ratio (HR) for PFS falls between 0.80 and 1.25. Ensuring a 70% probability that the observed HR will be "0.8 < HR < 1.25" under the assumption of the true HR of 1.0, and 100 patients will be evaluated during the 3-year study period. Secondary endpoints include overall survival, overall response rate, safety, and patient reported outcome (PRO) (FACT/GOG-Ntx4). DISCUSSION: Considering the lower incidence of hematologic toxicities with modified CAPIRI+BEV than with FOLFIRI+BEV, CAPOXIRI+BEV may be a promising treatment option if sufficient efficacy and lower hematologic toxicities are indicated in this study. Additionally, a lower incidence of peripheral sensory neuropathy (PSN) reported following CAPEOX treatment compared to that after FOLFOX in ACHIEVE, an adjuvant phase III trial, suggest that CAPOXIRI+BEV can mitigate OX-induced PSN. TRIAL REGISTRATION: Clinicaltrials.gov NCT04097444 . Registered September 20, 2019, https://clinicaltrials.gov/ct2/show/study/NCT04097444 / Japan Registry of Clinical Trials jRCTs041190072. Registered October 9, 2019.

RHBDD2 overexpression promotes a chemoresistant and invasive phenotype to rectal cancer tumors via modulating UPR and focal adhesion genes.

The current standard of care for locally advanced rectal cancer (RC) is neoadjuvant radio-chemotherapy (NRC) with 5-fluorouracil (5Fu) as the main drug, followed by surgery and adjuvant chemotherapy. While a group of patients will achieve a pathological complete response, a significant percentage will not respond to the treatment. The Unfolding Protein Response (UPR) pathway is generally activated in tumors and results in resistance to radio-chemotherapy. We previously showed that RHBDD2 gene is overexpressed in the advanced stages of colorectal cancer (CRC) and that it could modulate the UPR pathway. Moreover, RHBDD2 expression is induced by 5Fu. In this study, we demonstrate that the overexpression of RHBDD2 in CACO2 cell line confers resistance to 5Fu, favors cell migration, adhesion and proliferation and has a profound impact on the expression of both, the UPR genes BiP, PERK and CHOP, and on the cell adhesion genes FAK and PXN. We also determined that RHBDD2 binds to BiP protein, the master UPR regulator. Finally, we confirmed that a high expression of RHBDD2 in RC tumors after NRC treatment is associated with the development of local or distant metastases. The collected evidence positions RHBDD2 as a promising prognostic biomarker to predict the response to neoadjuvant therapy in patients with RC.

MRI Tumor Regression Grade and Circulating Tumor DNA as Complementary Tools to Assess Response and Guide Therapy Adaptation in Rectal Cancer.

PURPOSE: Response to preoperative chemo-radiotherapy (CRT) varies. We assessed whether circulating tumor DNA (ctDNA) might be an early indicator of tumor response or progression to guide therapy adaptation in rectal cancer. EXPERIMENTAL DESIGN: A total of 243 serial plasma samples were analyzed from 47 patients with localized rectal cancer undergoing CRT. Up to three somatic variants were tracked in plasma using droplet digital PCR. RECIST and MRI tumor regression grade (mrTRG) evaluated response. Survival analyses applied Kaplan-Meier method and Cox regression. RESULTS: ctDNA detection rates were: 74% (n = 35/47) pretreatment, 21% (n = 10/47) mid CRT, 21% (n = 10/47) after completing CRT, and 13% (n = 3/23) after surgery. ctDNA status after CRT was associated with primary tumor response by mrTRG (P = 0.03). With a median follow-up of 26.4 months, metastases-free survival was shorter in patients with detectable ctDNA after completing CRT [HR 7.1; 95% confidence interval (CI), 2.4-21.5; P < 0.001], persistently detectable ctDNA pre and mid CRT (HR 3.8; 95% CI, 1.2-11.7; P = 0.02), and pre, mid, and after CRT (HR 11.5; 95% CI, 3.3-40.4; P < 0.001) compared with patients with undetectable or nonpersistent ctDNA. In patients with detectable ctDNA, a fractional abundance threshold of ≥0.07% mid CRT or ≥0.13% after completing CRT predicted for metastases with 100% sensitivity and 83.3% specificity for mid CRT and 66.7% for CRT completion. All 3 patients with detectable ctDNA post-surgery relapsed compared with none of the 20 patients with undetectable ctDNA (P = 0.001). CONCLUSIONS: ctDNA identified patients at risk of developing metastases during the neoadjuvant period and post-surgery, and could be used to tailor treatment.

ARID3A Positivity Correlated With Favorable Prognosis in Patients With Residual Rectal Cancer After Neoadjuvant Chemoradiotherapy.

BACKGROUND/AIM: Recent studies have shown a marked increase of AT-rich interactive domain 3A (ARID3A) in colon cancer tissue compared to normal colon mucosa. However, the role of ARID3A has not yet been determined in rectal cancer. We, therefore, investigated the clinical relevance of ARID3A expression in patients with residual rectal cancer after neoadjuvant chemoradiotherapy (NACRT). MATERIALS AND METHODS: One hundred thirty-four patients who underwent surgical resection for residual rectal cancer after NACRT were analyzed. ARID3A expression was evaluated using immunohistochemistry on whole-tissue sections. KRAS exon 2 (codons 12 and 13) and BRAF V600E mutation status were determined using polymerase chain reaction. RESULTS: ARID3A positivity was found in 91 cases (64.5%), and it correlated with absence of perineural invasion (p=0.031), longer disease-free survival (DFS) (p=0.048) and cancer-specific survival (CSS) (p=0.006). However, ARID3A positivity was not correlated with KRAS (p=0.231) or BRAF mutation status (p=0.577). In multivariate analysis, ARID3A positivity was independently associated with a favorable CSS (p=0.035), but not DFS (p=0.051). CONCLUSION: ARID3A positivity can predict favorable prognosis in patients with residual rectal cancer after NACRT.

Thymidylate synthase gene polymorphism predicts disease free survival in stage II-III rectal adenocarcinoma patients receiving adjuvant 5-FU-based chemotherapy.

BACKGROUND: The objective is to investigate whether thymidylate synthase gene TS 5'-UTR polymorphism of peripheral blood mononuclear cells are associated with clinical outcomes of patients with stage II-III rectal adenocarcinoma treated with adjuvant 5-fluorouracil (5-FU) chemotherapy in Chinese population. METHODS: One hundred and seventeen pathologically diagnosed colorectal adenocarcinoma patients with stage II-III, who underwent curative resection and received 5-fluoropyrimidine-based adjuvant chemotherapy were enrolled to this study. The 5'-TSER polymorphisms determined from the peripheral blood mononuclear cells were measured by Direct Sequencing. Kaplan-Meier curves and log-rank tests were used for survival analysis. The independent prognostic factors influencing DFS and OS were estimated by Cox proportional hazards model. RESULTS: The distribution of TS 5'-UTR polymorphisms ware 2.6% 2R/2R, 31.6% 2R/3R and 65.8% 3R/3R respectively, which was fitted with Hard-Weinberg equilibrium (χ2=0.345, P=0.558). Stage, N stage, number of mesenteric lymph node metastasis, KPS, and 5'-UTR polymorphisms (2R/2R/2R/3R vs. 3R/3R, P<0.001) were significantly associated with DFS. Meanwhile, gender (female vs. male, P=0.025) and adjuvant radiotherapy (yes vs. no, P=0.025) were significantly associated with OS. Multivariate Cox regression showed that KPS score (HR =0.947, P=0.007), TS 5'-UTR polymorphism (HR =0.455, P=0.004) were independent prognostic factors for DFS. Whereas, KPS score was the only independent prognostic factors for OS (HR =0.910, P=0.005). CONCLUSIONS: TS 5'-UTR tandem repeat polymorphisms had potential utilization for personalized therapy in Chinese population.

Hemoglobin level and XRCC1 polymorphisms to select patients with locally advanced rectal cancer candidate for neoadjuvant chemoradiotherapy with concurrent capecitabine and a platinum salt.

A platinum salt (oxaliplatin or cisplatin) is widely used to enhance chemoradation (CRT) response. The potential of cisplatin in neoadjuvant CRT for locally advanced rectal cancer (LARC) has not been fully investigated. Consecutive patients with histologically confirmed LARC were treated with standard pelvic radiotherapy and concurrent cisplatin plus capecitabine (CisCape CRT). Surgery and eight cycles of adjuvant FOLFOX4 were offered to all patients after CRT. Common biochemical variables and key germline genetic polymorphisms were analyzed as predictors of pathological complete response (pCR). Fifty-one patients were enrolled. pCR (regression AJCC grade 0) was documented in 7 patients (14%), nearly complete response (AJCC grade 1) in 10 pts. There was a strong association between disease-free survival and AJCC grade (p 0.0047). Grade 3-4 toxicities (mainly diarrhea) was observed in 41% of patients. Among all analyzed variables, baseline hemoglobin (Hb) was significantly associated with AJCC grade 0-1 response (p 0.027). As for the pharmacogenetic analysis, XRCC1 rs25487 polymorphism was significantly associated with AJCC grade 0-1, Odds Ratio 25.8, p 0.049. AJCC grade 0-1 response rate for patients with high Hb and/or XRCC1 rs25487 G/G genotype was as high as 57%. Baseline Hb and XRCC1 polymorphisms are valuable selection criteria for the CisCape CRT regimen, given its otherwise meaningful toxicity.

Neoadjuvant radiotherapy combined with capecitabine and sorafenib in patients with advanced KRAS-mutated rectal cancer: A phase I/II trial (SAKK 41/08).

BACKGROUND: KRAS mutation occurs in ∼40% of locally advanced rectal cancers (LARCs). The multitarget tyrosine kinase inhibitor sorafenib has radiosensitising effects and might improve outcomes for standard preoperative chemoradiotherapy in patients with KRAS-mutated LARC. METHODS: Adult patients with KRAS-mutated T3/4 and/or N1/2M0 LARC were included in this phase I/II study. The phase I dose-escalation study of capecitabine plus sorafenib and radiotherapy was followed by a phase II study assessing efficacy and safety. Primary end-points were to: establish the maximum tolerated dose of the regimen in phase I; determine the pathologic complete response (pCR) rate in phase II defined as Dworak regression grade 3 and 4. RESULTS: Fifty-four patients were treated at 18 centres in Switzerland and Hungary; 40 patients were included in the single-arm phase II study. Recommended doses from phase I comprised radiotherapy (45 Gy in 25 fractions over 5 weeks) with capecitabine 825 mg/m2 twice daily × 33 plus sorafenib 400 mg/d. Median daily dose intensity in phase II was radiotherapy 100%, capecitabine 98.6%, and sorafenib 100%. The pCR rate (Dworak 3/4) was 60% (95% CI, 43.3-75.1%) by central independent pathologic review. Sphincter preservation was achieved in 89.5%, R0 resection in 94.7%, and downstaging in 81.6%. The most common grade 3 toxicities during phase II included diarrhoea (15.0%), skin toxicity outside radiotherapy field (12.5%), pain (7.5%), skin toxicity in radiotherapy field, proctitis, fatigue and cardiac ischaemia (each 5%). CONCLUSIONS: Combining sorafenib and standard chemoradiotherapy with capecitabine is highly active in patients with KRAS-mutated LARC with acceptable toxicity and deserves further investigation. www.clinicaltrials.gov: NCT00869570.

[Effect of resveratrol in regulating proliferation and apoptosis of rectal cancer cells via up-regulating PTEN].

To analysis the relative expression of PTEN(phosphatase and tensin homology deleted on chromosome ten) in rectal cancer cell lines and the effects of resveratrol on cell proliferation and apoptosis of rectal cancer cells in vitro. Western blot was used to assess the protein expression of PTEN in rectal cancer cell lines and non-malignant colon epithelial cell line. After treating human rectal cancer cell line SW480 with different concentrations of resveratrol, the cellular proliferation was detected by cell counting Kit-8(CCK-8) assay. The apoptotic rate was analyzed by flow cytometry. The protein expressions of Caspase-3, PTEN, p53 and phosphorylase AKT(p-AKT) were detected by Western blot. shRNA(short hairpin RNA) was built to down-regulate PTEN expression in SW480 cells, and detect whether the own-regulated PTEN expression impact resveratrol's effect in growth inhibition and apoptosis induction of in vitro rectal cancer cells. Our results demonstrated that the relative level of PTEN was markedly decreased in Caco-2 and SW480, with statistically significant differences(P<0.001). Resveratrol inhibited the proliferation of rectal cancer cells markedly, and triggered apoptosis of SW480 cells. The protein expressions of Caspase-3, PTEN and p53 were all increased after being treated with resveratrol, while the expression of p-AKT was decreased after the treatment. The expression of endogenous PTEN was significantly decreased in shRNA PTEN-infected SW480 cells. Meanwhile, shRNA PTEN could obviously reduce SW480 cells' anti-proliferative and apoptotic effects. The experimental results suggested that resveratrol can be used as an anti-proliferative and apoptosis induction agent in rectal cancer through up-regulation of PTEN.

A phase II study of preoperative chemoradiation with tegafur-uracil plus leucovorin for locally advanced rectal cancer with pharmacogenetic analysis.

BACKGROUND: This study aimed to evaluate the efficacy of a high dose of oral tegafur-uracil (400 mg/m2) plus leucovorin with preoperative chemoradiation of locally advanced rectal cancer and to explore the impact of polymorphisms of cytochrome P 2A6 (CYP2A6), uridine monophosphate synthetase (UMPS), and ATP-binding cassette B1 (ABCB1) on clinical outcome. METHODS: Patients with cT3 or cT4 rectal cancer were enrolled and were given tegafur-uracil 400 mg/m2/day and leucovorin 90 mg/m2/day for 7 days a week during preoperative chemoradiation (50.4 Gy/28 fractions) in this phase II trial. Primary endpoint was pathologic complete response rate, and the secondary endpoint was to explore the association between clinical outcomes and genetic polymorphisms CYP2A6 (*4, *7, *9 and *10), UMPS G638C, and three ABCB1 genotypes (C1236T, C3435T, and G2677T). RESULTS: Ninety-one patients were given study treatment, and 90 underwent surgery. Pathologic complete response was noted in 10 patients (11.1%). There was no grade 4 or 5 toxicity; 20 (22.0%) experienced grade 3 toxicities, including diarrhea (10, 11.0%), abdominal pain (2, 2.2%), and anemia (2, 2.2%). Relapse-free survival and overall survival at 5 years were 88.6% and 94.2%, respectively. Patients with the UMPS 638 CC genotype experienced significantly more frequent grade 2 or 3 diarrhea (p for trend = 0.018). CONCLUSIONS: Preoperative chemoradiation with tegafur-uracil 400 mg/m2/day with leucovorin was feasible, but did not meet the expected pathologic complete response rate. The UMPS 638 CC genotype might be a candidate biomarker predicting toxicity in patients receiving tegafur-uracil/leucovorin-based preoperative chemoradiation for locally advanced rectal cancer. TRIAL REGISTRATION: ISRCTN11812525 , registered on 25 July 2016. Retrospectively registered.

Synchronous quintuple primary gastrointestinal tract malignancies: Case report.

Multiple primary malignancy is defined as two or more malignancies detected in an individual person. In particular, synchronous quintuple primary malignancy is extremely rare. A 52-year-old male with anal pain and intermittent blood-tinged stool was diagnosed with malignancies in the stomach, jejunum, ascending colon, transverse colon and rectum. He underwent a subtotal gastrectomy, segmental resection of the jejunum and total protocolectomy with end ileostomy. The postoperative pathologic findings were moderate differentiated gastric adenocarcinoma (pT1bN0M0, pStageIA), combined adenocarcinoma and neuroendocrine carcinoma of the jejunum (pT3N0M0, pStageIIA), three mucinous adenocarcinoma of the ascending colon (pT3N0M0, pStageIIA), transverse colon (pT1N0M0, pStageI) and rectum (pT3N1aM0, pStageIIIB). The tumors did not lack MLH-1 and MSH-2 expression, as the markers (bat26, D5S346, bat25, D2S123) suggest MSI-H presence. Adjuvant chemoradiotherapy was started according to regimen, FOLFOX 4 for advanced rectal cancer. Six years post-operation, the patient is currently attending regular follow-ups without recurrence or metastasis.

Peritoneal carcinomatosis of colorectal cancer: novel clinical and molecular outcomes.

BACKGROUND: The objective of this study was to identify the prognostic impact of parameters in peritoneal carcinomatosis from colorectal cancer. METHODS: We collected data from patients treated by cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy for peritoneal carcinomatosis secondary to colorectal cancer. RESULTS: Ninety-one procedures were performed. In univariate analysis, an increased peritoneal cancer index was associated with decreased survival (P < .001). The presence of signet ring cells was associated to a decrease in survival from 45.8 to 12.1 months (P < .001). Microsatellite sequences instability status was the only molecular prognostic factor correlated with an increase in median disease-free survival: 12.4 vs 24.9 months (P = .01). The presence of a mucinous component was associated with a decreased of survival from 51.9 to 35.1 months (P = .02). CONCLUSIONS: Clinical factors were affecting the survival of patients. The absence of signet ring cells and mucinous component and the presence of microsatellite sequences instability may be favorable prognostic factors.

DNA Mismatch Repair Deficiency in Rectal Cancer: Benchmarking Its Impact on Prognosis, Neoadjuvant Response Prediction, and Clinical Cancer Genetics.

PURPOSE: DNA mismatch repair deficiency (dMMR) hallmarks consensus molecular subtype 1 of colorectal cancer. It is being routinely tested, but little is known about dMMR rectal cancers. The efficacy of novel treatment strategies cannot be established without benchmarking the outcomes of dMMR rectal cancer with current therapy. We aimed to delineate the impact of dMMR on prognosis, the predicted response to fluoropyrimidine-based neoadjuvant therapy, and implications of germline alterations in the MMR genes in rectal cancer. METHODS: Between 1992 and 2012, 62 patients with dMMR rectal cancers underwent multimodality therapy. Oncologic treatment and outcomes as well as clinical genetics work-up were examined. Overall and rectal cancer-specific survival were calculated by the Kaplan-Meier method. RESULTS: The median age at diagnosis was 41 years. MMR deficiency was most commonly due to alterations in MSH2 (53%) or MSH6 (23%). After a median follow-up of 6.8 years, the 5-year rectal cancer-specific survival was 100% for stage I and II, 85.1% for stage III, and 60.0% for stage IV disease. Fluoropyrimidine-based neoadjuvant chemoradiation was associated with a complete pathologic response rate of 27.6%. The extent of surgical resection was influenced by synchronous colonic disease at presentation, tumor height, clinical stage, and pelvic radiation. An informed decision for a limited resection focusing on proctectomy did not compromise overall survival. Five of the 11 (45.5%) deaths during follow-up were due to extracolorectal malignancies. CONCLUSION: dMMR rectal cancer had excellent prognosis and pathologic response with current multimodality therapy including an individualized surgical treatment plan. Identification of a dMMR rectal cancer should trigger germline testing, followed by lifelong surveillance for both colorectal and extracolorectal malignancies. We herein provide genotype-specific outcome benchmarks for comparison with novel interventions.

Endoscopic ultrasound fine-needle aspiration cytology mutation profiling using targeted next-generation sequencing: personalized care for rectal cancer.

OBJECTIVES: In an era of precision medicine, our aim was to determine the frequency and theranostic potential of mutations identified in malignant lymph nodes (LNs) sampled by endoscopic ultrasound fine-needle aspiration (EUS FNA) of patients with rectal cancer by targeted next-generation sequencing (NGS). METHODS: The NGS Ion AmpliSeq Cancer Hotspot Panel v2 (Life Technologies, Carlsbad, CA) and MiSeq (Illumina, San Diego, CA) sequencers were used to sequence and assess for 2,800 or more possible mutations in 50 established cancer-associated genes. RESULTS: Among 102 patients, 89% had 194 pathogenic alterations identified in 19 genes. The identification of KRAS, NRAS, or BRAF mutations suggests that 42% are likely nonresponders to anti-epidermal growth factor receptor therapy. Among KRAS, NRAS, or BRAF wild-type patients, alterations in eight genes linked to alternative therapies were identified in 44%. CONCLUSIONS: Our data demonstrate the successful ability to apply a single multiplex test to allow multigene mutation detection from malignant LN cytology specimen DNA collected by EUS FNA.

Carcinoma microsatellite instability status as a predictor of benefit from fluorouracil-based adjuvant chemotherapy for stage II rectal cancer.

PURPOSE: Rectal cancers with high microsatellite-instable have clinical and pathological features that differentiate them from microsatellite-stable or low- frequency carcinomas, which was studied rarely in stage II rectal cancer, promoting the present investigation of the usefulness of microsatellite-instability status as a predictor of the benefit of adjuvant chemotherapy with fluorouracil in stage II rectal cancer. PATIENTS AND METHODS: Data of 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2008 to 2012 were retrospectively collected. All patients experienced a total mesorectal excision (TME) operation. Survival analysis were analyzed using the Cox regression method. RESULTS: Five-year rate of disease-free survival (DFS) was noted in 390 (84.8%) of 460 patients with stage II rectal cancer. Of 460 tissue specimens, 97 (21.1%) exhibited high-frequency microsatellite instability. Median age of the patients was 65 (50-71) and 185 (40.2%) were male. After univariate and multivariate analysis, microsatellite instability (p= 0.001), female sex (p< 0.05) and fluorouracil-based adjuvant chemotherapy (p< 0.001), the 3 factors were attributed to a favorable survival status independently. Among 201 patients who did not receive adjuvant chemotherapy, those cancers displaying high-frequency microsatellite instability had a better 5-year rate of DFS than tumors exhibiting microsatellite stability or low-frequency instability (HR, 13.61 [95% CI, 1.88 to 99.28]; p= 0.010), while in 259 patients who received adjuvant chemotherapy, there was no DFS difference between the two groups (p= 0.145). Furthermore, patients exhibiting microsatellite stability or low-frequency instability who received adjuvant chemotherapy had a better 5-year rate of DFS than patients did not (HR, 5.16 [95% CI, 2.90 to 9.18]; p< 0.001), while patients exhibiting high-frequency microsatellite instability were not connected with increased DFS (p= 0.696). It was implied that female patients had better survival than male. CONCLUSION: Survival status after anterior resection of rectal carcinoma is related to the microsatellite instability status, adjuvant chemotherapy and gender. Fluorouracil-based adjuvant chemotherapy benefits patients of stage II rectal cancer with microsatellite-stable or low microsatellite-instable, but not those with high microsatellite- instable. Additionally, free of adjuvant chemotherapy, carcinomas with high microsatellite-instable have a better 5-year rate of DFS than those with microsatellite-stable or low microsatellite-instable, and female patients have a better survival as well.

Pharmacogenetic Analysis of INT 0144 Trial: Association of Polymorphisms with Survival and Toxicity in Rectal Cancer Patients Treated with 5-FU and Radiation.

PURPOSE: We tested whether 18 polymorphisms in 16 genes (GSTP1, COX2, IL10, EGFR, EGF, FGFR4, CCDN1, VEGFR2, VEGF, CXCR2, IL8, MMP3, ICAM1, ERCC1, RAD51, and XRCC3) would predict disease-free survival (DFS), overall survival (OS), and toxicity in the INT0144 trial, which was designed to investigate different postoperative regimens of 5-fluorouracil (5-FU)-based chemoradiation (CRT) in locally advanced rectal cancers: Arm 1 consisted of bolus 5-FU followed by 5-FU protracted venous infusion (PVI) with radiotherapy; arm 2 was induction and concomitant PVI 5-FU with radiotherapy and arm 3 was induction and concomitant bolus 5-FU with radiotherapy. EXPERIMENTAL DESIGN: DNA from 746 stage II/III rectal patients enrolled in the Southwest Oncology Group (SWOG) S9304 phase III trial was analyzed. Genomic DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue. The polymorphisms were analyzed using direct DNA-sequencing or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: GSTP1-Ile105Val (rs1695) was significantly associated with DFS and OS and its effect did not vary by treatment arm. The five-year DFS and OS were 53% and 58%, respectively, for G/G, 66% and 72% for G/A, and 57% and 66% for A/A patients. In arm 2, IL8-251A/A genotype (rs4073) was associated with a lower risk of toxicities (P = 0.04). The VEGFR2 H472Q Q/Q genotype (rs1870377) was associated with a higher risk of grade 3-5 proximal upper gastrointestinal tract (PUGIT) mucositis (P = 0.04) in arm 2. However, in arm 1, this genotype was associated with a lower risk of PUGIT mucositis (P = 0.004). CONCLUSION: rs1695 may be prognostic in patients with rectal cancer treated with adjuvant CRT. rs4073 and rs1870377 may exhibit different associations with toxicity, according to the 5-FU schedule.

Association between the cytogenetic profile of tumor cells and response to preoperative radiochemotherapy in locally advanced rectal cancer.

Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results.