Preoperative chemoradiotherapy with 5-fluorouracil and oxaliplatin for locally advanced rectal cancer: long-term results of a phase II trial

The Impact of DTYMK as a Prognostic Marker in Colorectal Cancer

Background

Overexpression of deoxythymidylate kinase (DTYMK) has been associated with more aggressiveness and pathological behaviors in hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC). However, the expression of DTYMK and its prognostic significance in colorectal cancer (CRC) patients are yet unknown. The goal of this study was to investigate the DTYMK immunohistochemistry reactivity in CRC tissues and to see how it correlated with various histological and clinical features as well as survival.

Methods

Several bioinformatics databases and two tissue microarrays (TMAs) of 227 cases were used in this study. Immunohistochemistry assay was used to study the protein expression of DTYMK.

Results

Based on the GEPIA, UALCAN, and Oncomine databases, DTYMK expression has increased in tumor tissues at both RNA and protein levels in colorectal adenocarcinoma (COAD) compared to normal tissues. A high DTYMK H-score was found in 122/227 (53%) of the cases, whereas a low DTYMK H-score was found in 105/227. The age at diagnosis (P = 0.036), stage of the disease (P = 0.038), and site of origin (P = 0.032) were all linked to a high DTYMK H-score. Patients with high level of DTYMK had bad overall survival. Interestingly, high DTYMK protein level was associated with PSM2 (P = 0.002) and MSH2 (P = 0.003), but not with MLH2 or MSH6.

Conclusion

This is the first study to cover the expression and prognostic significance of DTYMK in CRC. DTYMK was upregulated in CRC and could be considered as a prognostic biomarker.

Prognostic significance of BIRC7/Livin, Bcl-2, p53, Annexin V, PD-L1, DARC, MSH2 and PMS2 in colorectal cancer treated with FOLFOX chemotherapy with or without aspirin

Evasion of apoptosis is associated with treatment resistance and metastasis in colorectal cancer (CRC). Various cellular processes are associated with evasion of apoptosis. These include overexpression of pro-apoptotic proteins (including p53 and PD-L1), anti-apoptotic proteins (BIRC7/Livin and Bcl-2), chemokine receptors (including DARC), and dysregulation of DNA mismatch repair proteins (including MSH2 and PMS2). The aim of this study was to determine the effect of folinic acid, 5-FU and oxaliplatin (FOLFOX) as a single agent and aspirin plus FOLFOX in various combinations on the aforementioned proteins in human CRC, SW480 cell line and rat models of N-Methyl-N-Nitrosourea (NMU)-induced CRC. In addition, effects of the NMU-induced CRC and chemotherapeutic regimens on haematological and biochemical parameters in the rat models were studied. Immunohistochemistry, immunofluorescence and immunoblot techniques were used to study the expression pattern of the related proteins in the human CRC cells pre- and post-treatment. Double contrast barium enema, post-mortem examination and histological analyses were used to confirm tumour growth and the effect of the treatment in vivo in rat models. Notably, we found in human mucinous CRC, a significant increase in expression of the BIRC7/Livin post-FOLFOX treatment compared with pre-treatment (p = 0.0001). This increase provides new insights into the prognostic role of BIRC7/Livin in evasion of apoptosis and facilitation of treatment resistance, local recurrence and metastasis particularly among mucinous CRCs post-FOLFOX chemotherapy. These poor prognostic features in the CRC may be further compounded by the significant suppression of DARC, PD-L1, PMS2 and overexpression of MSH2 and anti-apoptotic Bcl-2 and p53 proteins observed in our study (p < 0.05). Importantly, we found a significant reduction in expression of BIRC7/Livin and reactivation of DARC and PD-L1 with a surge in Annexin V expression in rat models of CRC cells post-treatment with a sequential dose of aspirin plus FOLFOX compared with other treatments in vivo (p <0.05). The mechanistic rational of these effects underscores the importance of expanded concept of possible aspirin combination therapy with FOLFOX sequentially in future CRC management. Validation of our findings through randomized clinical trials of aspirin plus FOLFOX sequentially in patients with CRC is therefore warranted.

Total mesorectal excision with or without preoperative chemoradiotherapy for resectable mid/low rectal cancer: a long-term analysis of a prospective, single-center, randomized trial

BACKGROUND

The preliminary results of our phase II randomized trial reported comparable functional sphincter preservation rates and short-term survival outcomes between patients undergoing total mesorectal excision (TME) with or without preoperative concurrent chemoradiotherapy (CCRT). We now report the long-term results after a median follow-up of 71 months.

METHODS

Between March 23, 2008 and August 2, 2012, 192 patients with T3-T4 or node-positive, resectable, mid/low rectal adenocarcinoma were randomly assigned to receive TME with or without preoperative CCRT. The following endpoints were assessed: cumulative rates of local recurrence and distant metastasis, disease-free survival (DFS), and overall survival (OS).

RESULTS

The data of 184 eligible patients were analyzed: 94 patients in the TME group and 90 patients in the CCRT + TME group. In the whole cohort, the 5-year DFS and OS rates were 84.8% and 85.1%, respectively. The 5-year DFS rates were 85.2% in the CCRT + TME group and 84.3% in the TME group (P = 0.969), and the 5-year OS rates were 83.5% in the CCRT + TME group and 86.5% in the TME group (P = 0.719). The 5-year cumulative rates of local recurrence were 6.3% and 5.0% (P = 0.681), and the 5-year cumulative rates of distant metastasis were 15.0% and 15.7% (P = 0.881) in the CCRT + TME and TME groups, respectively. No significant improvements in 5-year DFS and OS were observed with CCRT by subgroup analyses.

CONCLUSIONS

Both treatment strategies yielded similar long-term outcomes. A selective policy towards preoperative CCRT is thus recommended for rectal cancer patients if high-quality TME surgery and enhanced chemotherapy can be performed. Trial registration ChiCTR-TRC-08000122. Registered 16 July 2008.

Addition of oxaliplatin to capecitabine-based preoperative chemoradiotherapy for locally advanced rectal cancer: Long-term outcome of a phase II study

Our previous study reported the favorable short-term outcome and good tolerance of integrating oxaliplatin into capecitabine-based (XELOX regimen) preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). The present study reported the long-term oncological outcome of this phase II study. A total of 47 patients with rectal adenocarcinoma (stage II or III) were enrolled and received radiotherapy (46 Gy in 23 fractions) in combination with capecitabine (1,000 mg/m², twice daily, on days 1–14 and 22–35) and oxaliplatin (130 mg/m² on days 1 and 22). Overall survival (OS) rate, disease-free survival (DFS) rate and cumulative incidence of recurrences and long-term complications were calculated or observed. As a result, 41 patients underwent surgery after preoperative CRT, and the cumulative OS rates at 1, 3 and 5 years for these patients were 100.0, 84.5 and 81.8%, respectively. For the 38 patients who received R0 resection, the cumulative OS rates at 1, 3 and 5 years were 100.0, 89.0 and 86.2%, respectively, while the cumulative DFS rates at 1, 3 and 5 years were 94.6, 75.3 and 69.7%, respectively. After follow-up at 84 months, the cumulative incidence rates of local and distant recurrences at 5 years were 6.6 and 28.2%, respectively. Oxaliplatin-associated long-term complications were seldom observed. Overall, the addition of oxaliplatin to capecitabine-based preoperative radiotherapy achieved favorable OS and DFS without increased long-term complications in patients with LARC. Therefore, this preoperative CRT strategy is a feasible option for such patients.

Phase 2 Neoadjuvant Treatment Intensification Trials in Rectal Cancer: A Systematic Review

PURPOSE

Multiple phase 2 trials of neoadjuvant treatment intensification in locally advanced rectal cancer have reported promising efficacy signals, but these have not translated into improved cancer outcomes in phase 3 trials. Improvements in phase 2 trial design are needed to reduce these false-positive signals. This systematic review evaluated the design of phase 2 trials of neoadjuvant long-course radiation or chemoradiation therapy treatment intensification in locally advanced rectal cancer.

METHODS AND MATERIALS

The PubMed, EMBASE, MEDLINE, and Cochrane Library databases were searched for published phase 2 trials of neoadjuvant treatment intensification from 2004 to 2016. Trial clinical design and outcomes were assessed, with statistical design and compliance rated using a previously published system. Multivariable meta-regression analysis of pathologic complete response (pCR) was conducted.

RESULTS

We identified 92 eligible trials. Patients with American Joint Committee on Cancer stage II and III equivalent disease were eligible in 87 trials (94.6%). In 43 trials (46.7%), local staging on magnetic resonance imaging was mandated. Only 12 trials (13.0%) were randomized, with 8 having a standard-treatment control arm. Just 51 trials (55.4%) described their statistical design, with 21 trials (22.8%) failing to report their sample size derivation. Most trials (n=84, 91.3%) defined a primary endpoint, but 15 different primary endpoints were used. All trials reported pCR rates. Only 38 trials (41.3%) adequately reported trial statistical design and compliance. Meta-analysis revealed a pooled pCR rate of 17.5% (95% confidence interval, 15.7%-19.4%) across treatment arms of neoadjuvant long-course radiation or chemoradiation therapy treatment intensification and substantial heterogeneity among the reported effect sizes (I² = 55.3%, P<.001). Multivariable meta-regression analysis suggested increased pCR rates with higher radiation therapy doses (adjusted P=.025).

CONCLUSIONS

Improvement in the design of future phase 2 rectal cancer trials is urgently required. A significant increase in randomized trials is essential to overcome selection bias and determine novel schedules suitable for phase 3 testing. This systematic review provides key recommendations to guide future treatment intensification trial design in rectal cancer.

Outcomes of Young Patients With Rectal Cancer From a Tertiary Cancer Care Centre in India

BACKGROUND

Carcinoma of the rectum is the fourth most common cancer in the world. The peak age of diagnosis is around the seventh decade. Rectal cancer presenting in those < 35 years old are very peculiar in that they present with adverse histologic features and more advanced stage compared with rectal cancer presenting in older patients.

MATERIALS AND METHODS

We retrospectively evaluated the patient records of young patients with rectal cancer (aged < 35 years) treated in our unit at the All India Institute from 2007 to 2013.

RESULTS

A total of 60 young patients with rectal cancer were registered in our unit during the study period. A family history of cancer was present in 3 patients. The median age at presentation was 27.5 years (range, 15-34 years). The male-to-female ratio was 1.5:1. Of the 60 patients, 52 (86.6%) presented with advanced-stage disease (stage III and IV). Mucinous, signet, papillary, and other poor-risk histologic features were seen in 33 patients (55%). The treatment intention was radical for 50 patients (83.3%). The median follow-up period was 7.3 months. Eighteen patients had documented disease progression. Distant metastasis was the most common type of failure, seen in 14 of 18 patients (77%). The median progression-free survival (PFS) was 1.4 years. The 1- and 3-year PFS rates were 66.5% and 42.0%, respectively. On univariate analysis, the Karnofsky performance status and histologic type were significant prognostic factors for PFS.

CONCLUSION

A greater proportion of poor histologic subtypes was found among young patients with rectal cancer. The high incidence of poor histologic subtypes confers a poor prognosis in these patients.