Combined modality therapy for rectal cancer. Cancer J. 2010;16:253-261. [PMID: 20526104 DOI: 10.1097/ppo.0b013e3181e0761c]

Association of Adjuvant Chemotherapy With Overall Survival in Patients With Rectal Cancer and Pathologic Complete Response Following Neoadjuvant Chemotherapy and Resection

Importance

Adjuvant chemotherapy (AC) in patients with rectal cancer with pathologic complete response following neoadjuvant chemoradiotherapy (nCRT) and resection is recommended by treatment guidelines. However, its role in this setting is equivocal because data supporting benefits are lacking.

Objective

To compare the overall survival (OS) between AC and postoperative observation (OB) in patients with rectal cancer with pathologic complete response following nCRT and resection.

Design, Setting, and Participants

We identified a cohort of patients with rectal cancer and a complete pathological response (ypT0N0) after nCRT in the National Cancer Database between 2006 and 2012. Patients who received AC were compared with OB patients by propensity score matching. Overall survival was compared using the stratified log-rank test and stratified Cox regression model. The outcomes after AC vs OB were also evaluated in patient subgroups. The data analysis was completed in June 2017.

Exposures

Adjuvant chemotherapy and OB.

Main Outcomes and Measures

Overall survival.

Results

We identified 2764 patients (mean [SD] age, 60.0 [12.3] years; 40% female) with clinical stage II or III resected adenocarcinoma of the rectum who had received nCRT and were complete responders (ypT0N0M0). Of this cohort, 741 patients in the AC group were matched by propensity score to 741 patients who underwent OB. The AC cohort had better OS compared with the OB cohort (hazard ratio, 0.50; 95% CI, 0.32-0.79). The 1-, 3-, and 5-year OS rates were 99.7%, 97.1%, and 94.7% for the AC group and 99.2%, 93.6%, and 88.4% for the OB group (P = .005). In subgroup analysis, patients with clinical stage T3/T4 and node-positive disease benefited most from AC (hazard ratio, 0.47; 95% CI, 0.25-0.91).

Conclusions and Relevance

Adjuvant chemotherapy was associated with improved OS in patients with pathologic complete response after nCRT for resected locally advanced rectal cancer. This study supports the use of AC in this setting where there is currently paucity of data.

The effects of chemoradiotherapy on recurrence and survival in locally advanced rectal cancers with curative total mesorectal excision: a prospective, nonrandomized study

Background

There are only two prospective, randomized studies comparing preoperative long-term chemoradiotherapy and postoperative chemoradiotherapy in locally advanced rectal cancer (LARC); however, conflicting results in terms of locoregional recurrence (LR) and survival rates have been reported. This prospective study aims to compare the effects of preoperative versus postoperative chemoradiotherapy on recurrence and survival rates in LARC patients.

Methods

From January 2003 to January 2016, a total of 336 eligible patients who were clinically diagnosed with LARC (T₃–T₄ tm or node-positive disease) were prospectively assigned into preoperative chemoradiotherapy (n = 177) and postoperative chemoradiotherapy (n = 159) groups. The preoperative treatment consisted of 50.4 Gy total dose of radiotherapy (delivered in fractions of 1.8 Gy) and concomitant two cycles chemotherapy of 5-fluorouracil and leucovorin. The patients in the preoperative group underwent curative total mesorectal excision (TME) following long-term chemoradiotherapy. Surgery was performed 8 (range 4–12) median weeks after the completion of the chemoradiotherapy. Similar protocol was administered to the postoperative group 4 weeks after the operation. Four cycles of adjuvant chemotherapy were added to the groups. The primary end points were locoregional recurrences and 5-year cancer-specific, overall, and disease-free survivals.

Results

The mean follow-up period was 60.4 (range 12 to 168) months. Five-year cumulative incidence of locoregional recurrence (LR) was 7.4% in the preoperative group and 13.4% in the postoperative group (p = 0.021). Five-year cancer-specific survival (CSS) was 87.5% in the preoperative group and 80% in the postoperative group (p = 0.022). Overall survival (OS) was 79.8 versus 74.7% (p = 0.064), disease-free survival (DFS) was 75.2 versus 64.8% (p = 0.062), and severe late toxicity was 7.4 versus 13.2% (p = 0.002), respectively. The rate of patient compliance was higher in the preoperative group (p < 0.001).

Conclusions

Preoperative chemoradiotherapy, as compared with postoperative chemoradiotherapy, significantly improved local control, patient compliance, CSS, and late toxicity and suggested a trend toward improved overall and disease-free survival.

Phase I dose escalation trial of nitroglycerin in addition to 5-fluorouracil and radiation therapy for neoadjuvant treatment of operable rectal cancer

BACKGROUND

Nitric oxide donors decreased cell survival in vitro and tumor load in vivo in models of rectal cancer subjected to ionizing radiation. Nitroglycerin (NTG) transdermal patches, added to chemotherapy, have been shown to improve outcomes in lung cancer patients.

METHODS

This open-label, nonrandomized, multicohort, dose escalation, phase I trial had a primary endpoint to evaluate the safety, tolerability, feasibility, dose-limiting toxicity and maximum tolerated dose of topical NTG in addition to 5-fluorouracil and radiation therapy for neoadjuvant treatment of locoregionally advanced operable rectal cancer. The secondary endpoint was rate of pathologic complete response (pCR). Patients were assigned to 3 sequential cohorts of escalating dose levels of commercially available NTG patches (0.2, 0.4, and 0.6 mg/h), each cohort was intended to consist of 3 patients.

RESULTS

Thirteen patients were enrolled in the trial as specified in the dose escalation protocol. They were all male with a median age of 59.4 ± 2.5 (SEM) years. The observed toxicities were mild to moderate and manageable. Four patients developed asymptomatic grade 3 lymphopenia during the chemoradiation that resolved promptly upon completion. One patient had a non-ST segment elevation MI and 1 patient developed diarrhea. None of these toxicities were attributed to NTG except for 1 patient who developed a grade 3 headache. This required an additional group of patients at the same dose and no other patient experienced headaches. pCR was 17%.

CONCLUSION

NTG patches are well-tolerated and it is feasible to proceed with a phase II trial at the maximum dose examined (0.6 mg/h).

Genotypic characteristics of resistant tumors to pre-operative ionizing radiation in rectal cancer

Due to a wide range of clinical response in patients undergoing neo-adjuvant chemoradiation for rectal cancer it is essential to understand molecular factors that lead to the broad response observed in patients receiving the same form of treatment. Despite extensive research in this field, the exact mechanisms still remain elusive. Data raging from DNA-repair to specific molecules leading to cell survival as well as resistance to apoptosis have been investigated. Individually, or in combination, there is no single pathway that has become clinically applicable to date. In the following review, we describe the current status of various pathways that might lead to resistance to the therapeutic applications of ionizing radiation in rectal cancer.

Chronicle: results of a randomised phase III trial in locally advanced rectal cancer after neoadjuvant chemoradiation randomising postoperative adjuvant capecitabine plus oxaliplatin (XELOX) versus control

BACKGROUND

In stage III colon cancer, oxaliplatin/5-fluorouracil (5-FU)-based adjuvant chemotherapy (FOLFOX) improves disease-free survival (DFS) and overall survival (OS). In rectal adenocarcinoma following neoadjuvant chemoradiation (CRT), we examined the benefit of postoperative adjuvant capecitabine and oxaliplatin (XELOX) chemotherapy.

METHODS

Eligible patients were randomly assigned following fluoropyrimidine-based CRT and curative resection to observation or six cycles of XELOX. The primary end point was DFS; secondary end points were acute toxicity and OS. 390 patients were required in each arm, to detect an improvement in 3-year DFS from 40% to 50.5%, with 85% power and two-sided 5% significance level.

RESULTS

The study closed prematurely in 2008 because of poor accrual. Only 113 patients were randomly assigned to either observation (n = 59) or XELOX (n = 54). Compliance was poor, 93% allocated chemotherapy started and 48% completed six cycles. Protocolised dose reductions in XELOX were 39%, and levels of G3/G4 toxicity 40%. After a median follow-up of 44.8 months, 16 patients (27%) in the observation arm had relapsed or died compared with 12 patients (22%) in XELOX. The 3-year DFS rate was 78% with XELOX and 71% with observation [hazard ratio (HR) for DFS = 0.80; 95% confidence interval (CI) 0.38-1.69; P = 0.56]. The 3-year OS for XELOX and observation were 89% and 88%, respectively (HR for OS = 1.18; 95% CI 0.43-3.26; P = 0.75).

CONCLUSIONS

The observed improvement in DFS for adjuvant XELOX and similar OS were not statistically significant, as expected given the small number of patients and consequent low power. Our findings support the need for trials that test the role of neoadjuvant chemotherapy.

CLINICALTRIALSGOV IDENTIFIER

NCT00427713.

Preoperative long course chemoirradiation in a developing country for rectal carcinoma: Kuala Lumpur hospital experience

BACKGROUND

The use of preoperative chemoirradiation is the commonest treatment strategy employed in Malaysia for locally advanced rectal cancer. We need to determine the local control and survival rates for comparison with established rates in the literature.

MATERIALS AND METHODS

This retrospective study analyzed all newly diagnosed patients with rectal adenocarcinoma who underwent long course preoperative radiotherapy (RT) at the Department of Radiotherapy and Oncology, Kuala Lumpur Hospital (HKL) between 1st January 2004 and 31st December 2010. The aim of the study was to determine the radiological response post radiotherapy, pathological response including circumferential resection margin (CRM) status, 3 years local control, 3 years overall survival (OS) and 3 years disease free survival (DFS). Statistical analysis was performed using the SPSS software. Kaplan-Meier and log rank analysis were used to determine survival outcomes.

RESULTS

A total of 507 patients with rectal cancer underwent RT at HKL. Sixty seven who underwent long course preoperative RT were eligible for this study. The median age at diagnosis was 60 years old with a range of 26-78 years. The median tumour location was 6 cm from the anal verge. Most patients had suspicion of mesorectum involvement (95.5%) while 28.4% of patients had enlarged pelvic nodes on staging CT scan. All patients underwent preoperative chemo-irradiation except for five who had preoperative RT alone. Only 38 patients underwent definitive surgery (56.7%). Five patients were deemed to be inoperable radiologically and 3 patients were found to have unresectable disease intraoperatively. The remaining 21 patients defaulted surgery (31.3%). The median time from completion of RT to surgery was 8 weeks (range 5.6 to 29.4 weeks). Fifteen patients (39.5%) had surgery more than 8 weeks after completion of RT. Complete pathological response was noted in 4 patients (10.5%). The pathological CRM positive rate after RT was 18.4%. With a median follow-up of 38.8 months, the 3 year local control rate was 67%. The 3 years rate for CRM positive (<2 mm), CRM clear (>2 mm) and pCR groups were 0%, 88.1% and 100% respectively (p-value of 0.007). The 3 year OS and DFS were 57.3% and 44.8% respectively.

CONCLUSIONS

In conclusion, the approach of long course preoperative chemoirradiation for rectal cancer needs to be re-examined in our local setting. The high rate of local recurrence is worrying and is mainly due to patient defaulting post-preoperative chemoirradiation or delayed definitive surgery.

Prospective phase II trial of neoadjuvant chemo-radiotherapy with Oxaliplatin and Capecitabine in locally advanced rectal cancer (XELOXART)

Neo-adjuvant chemo-radiotherapy (CT-RT) has been shown to decrease local recurrence rate in locally advanced rectal cancer. This multicenter phase II trial was conducted to evaluate the feasibility, safety and effectiveness of a combination of pre-operative radiotherapy and concurrent Capecitabine plus Oxaliplatin (XELOXART Trial). From October 2008 to May 2011, fifty consecutive patients affected with T3/T4 and/or N+ rectal cancer were enrolled. Treatment protocol consisted of 50.4 Gy in 28 fractions, Oxaliplatin 60 mg/m(2) once a week for 6 weeks and oral Capecitabine 825 mg/m(2) twice daily from day 1 to 14 and from day 22 to 35. Surgery was planned 6-8 weeks after. Main endpoints were pathological complete response rate (pCR) and the type of surgery performed compared to the planned one at diagnosis. 50 patients were included; pCR (ypT0N0M0) was achieved in 6 patients (12 %). Tumour downstaging was observed in 27 patients (54 %), and nodal downstaging in 32 patients (64 %). A total of 32 patients had lower rectal cancer, with 24 candidate for abdominal-perineal resection. At the end of CT-RT, a total of 12/24 (50 %) underwent conservative surgery. Grade 3 toxicity (fatigue and diarrhoea) occurred in 4 % of patients; grade 4 sensory neuropathy occurred in 2 % of patients. Perioperative complications of any grade occurred in 10 % of patients. Pre-operative CT-RT with Capecitabine-Oxaliplatin was well tolerated and resulted in an encouraging sphincter preservation and tumour downstaging rate. No improvements in terms of pathological complete response rate were shown.

Role of radiation therapy in neoadjuvant era in patients with locally advanced rectal cancer

Surgery remains the primary determinant of cure in patients with localized rectal cancer, and total mesorectal excision is now widely accepted as standard of care. The widespread implementation of neoadjuvant short-course radiotherapy (RT) or long-course chemoradiotherapy (CRT) has reduced local recurrence rates from 25% to 40% to less than 10%; Preoperative RT in resectable rectal cancer has a number of potential advantages, most importantly reducing local recurrence, and down-staging effect. In this article making a comprehensive literature review searching the reliable medical data bases of PubMed and Cochrane we present all available information on the role of radiation therapy alone or in combination with chemotherapy in preoperative setting of rectal cancer. Data reported show that in locally advanced rectal cancer the addition of radiation therapy or CRT pre surgically has significantly improved sphincter prevention surgery. Moreover, the addition of chemotherapy to radiation therapy in preoperative setting has significantly improved pathologic complete response rate and loco-regional control rate without improvement in sphincter preserving surgery. Finally, the results of recently published randomized trials have shown a significant improvement of pre- vs postoperative CRT on local control; however, there was no effect on overall survival.

Neoadjuvant short- or long-term radio(chemo)therapy for rectal cancer: how and who should be treated?

There are two general approaches to preoperative radiotherapy (RT) in rectal cancer: short-course (25 Gy in 5 fractions) radiation with immediate surgery and long-course 5-fluorouracil (5-FU)-based chemoradiotherapy (CRT; 50.4 Gy in 28 fractions) with surgery scheduled 6-8 weeks thereafter. While it is clear that downsizing and downstaging effects are more pronounced with long-course CRT and delayed surgery, a Polish randomized trial and, more recently, an Australian phase III trial demonstrated no significant differences in long-term oncologic outcomes and late toxicity rates between either preoperative concept. Ongoing studies currently address short-course preoperative RT with a longer interval to surgery (Stockholm III trial), and short-course RT with sequential combination chemotherapy in patients with synchronous distant metastasis. With respect to the long-course CRT approach, newer-generation chemotherapeutics as well as molecularly targeted agents have been tested within phase I-III studies, both as induction/adjuvant chemotherapy as well as during concomitant CRT. Evidently, the monolithic approaches to either apply the same schedule of preoperative 5-FU-based CRT to all patients with TNM stage II/III rectal cancer or to give preoperative short-course RT for all patients with resectable rectal cancer irrespective of tumor stage and location need to be questioned. The inclusion of different multimodal treatments into the surgical oncological concept, adapted to tumor location, stage, and individual patient risk factors and preferences is upcoming. Clearly, future developments will aim at identifying and selecting patients for ideal treatment alternatives.

Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: results of the German CAO/ARO/AIO-94 randomized phase III trial after a median follow-up of 11 years

PURPOSE

Preoperative chemoradiotherapy (CRT) has been established as standard treatment for locally advanced rectal cancer after first results of the CAO/ARO/AIO-94 [Working Group of Surgical Oncology/Working Group of Radiation Oncology/Working Group of Medical Oncology of the Germany Cancer Society] trial, published in 2004, showed an improved local control rate. However, after a median follow-up of 46 months, no survival benefit could be shown. Here, we report long-term results with a median follow-up of 134 months.

PATIENTS AND METHODS

A total of 823 patients with stage II to III rectal cancer were randomly assigned to preoperative CRT with fluorouracil (FU), total mesorectal excision surgery, and adjuvant FU chemotherapy, or the same schedule of CRT used postoperatively. The study was designed to have 80% power to detect a difference of 10% in 5-year overall survival as the primary end point. Secondary end points included the cumulative incidence of local and distant relapses and disease-free survival.

RESULTS

Of 799 eligible patients, 404 were randomly assigned to preoperative and 395 to postoperative CRT. According to intention-to-treat analysis, overall survival at 10 years was 59.6% in the preoperative arm and 59.9% in the postoperative arm (P = .85). The 10-year cumulative incidence of local relapse was 7.1% and 10.1% in the pre- and postoperative arms, respectively (P = .048). No significant differences were detected for 10-year cumulative incidence of distant metastases (29.8% and 29.6%; P = .9) and disease-free survival.

CONCLUSION

There is a persisting significant improvement of pre- versus postoperative CRT on local control; however, there was no effect on overall survival. Integrating more effective systemic treatment into the multimodal therapy has been adopted in the CAO/ARO/AIO-04 trial to possibly reduce distant metastases and improve survival.

Absence of MMP2 expression correlates with poor clinical outcomes in rectal cancer, and is distinct from MMP1-related outcomes in colon cancer

PURPOSE

Treatments for colorectal cancer (CRC) are primarily disease stage based. However, heterogeneity in outcome within even a single stage highlights its limitations in predicting disease behavior. Recently, the role of gene expression as predictive and prognostic markers has been explored. Our objectives were to identify consistently differentially expressed genes through meta-analysis of high-throughput gene-expression studies, and evaluate their predictive and prognostic significance in colon (CC) and rectal (RC) cancers.

EXPERIMENTAL DESIGN

Publications applying high-throughput gene- expression technologies to specific CRC stages were identified. A vote counting strategy was used to identify the most significant differentially expressed genes. Their predictive and prognostic values were independently assessed in a tissue microarray of 191 cases of stage II-IV CC/RC from two tertiary care centers. Their biological effects were also examined in vitro.

RESULTS

MMP1 and MMP2 were identified as consistently underexpressed in liver metastasis compared with primary CRC. Shorter time to distant metastasis and overall survival occurred in stage III CC lacking MMP1 expression, and in stage III RC lacking MMP2. MMP1 levels in stage II and III CC were associated with increased likelihood of distant metastasis, whereas the risk of local recurrence in stage III RC could be stratified by MMP2. Promotion of cell invasion of CRC cell lines exposed to MMP1/2 inhibitors were confirmed in vitro.

CONCLUSIONS

MMP1 and MMP2 may be useful biomarkers that can help stratify patients at higher risk of developing recurrence in colorectal cancer, and guide individualized treatment decisions to achieve better outcomes.