Advances in management of adjuvant chemotherapy in rectal cancer: Consequences for clinical practice

Multimodal Treatment of Rectal Cancer

BACKGROUND

Colorectal cancer is one of the three most common types of cancer in Germany. Approximately 30% of these cancers are located in the rectum, corresponding to about 18 000 new cases per year.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, including current guidelines and recommendations.

RESULTS

Specialized imaging, particularly magnetic resonance imaging, is essential for treatment planning. In very early stages of this disease, tumors without risk factors can be excised locally. Otherwise, radical surgical resection with lymphadenectomy remains the standard treatment, and can be performed either minimally invasive or open. At present, neoadjuvant treatment plans are evolving in the direction of total neoadjuvant therapy. In addition, recent studies investigate whether the improved efficacy of neoadjuvant therapy might now enable patients with a complete clinical remission to be spared from surgical resection (organ-preserving watch-and-wait strategy).

CONCLUSION

The treatment of rectal cancer is a prime example of an interdisciplinary, multimodal approach. In the past, the focus was mainly on improving oncologic outcomes; at present, increasing attention is being devoted to the patients' quality of life as well and the functional aspects of the various modes of treatment.

Is Early Initiation of Adjuvant Chemotherapy Beneficial for Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiotherapy and Radical Surgery?

AIM

This study aimed to evaluate whether earlier initiation (< 4 weeks) of adjuvant chemotherapy (ACT) confer any oncological benefits for locally advanced rectal cancer (LARC) patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgery.

METHOD

Clinicopathological and survival outcomes were compared. Propensity score matching (PSM) was performed to adjust for differences between groups. Cox regression analysis was performed to evaluate the impact of earlier ACT initiation on overall survival (OS) and disease-free survival (DFS).

RESULTS

Totally, 443 eligible patients were included. More laparoscopic surgeries, less postoperative complications, and more ACT completion were observed in patients whose ACT was initiated within 4 weeks after surgery (all P < 0.001). With a mean follow-up of 59 months, the 5-year OS and DFS rate was 89.8% and 82.0% in the early group, significantly higher than 81.6% and 73.1% in the late group (P = 0.007, and P = 0.022, respectively). After PSM, the 5-year OS and DFS rate was 90.9% and 84.4% in the early group, significantly higher than 83.4% and 68.8% in the late group (P = 0.047, and P = 0.017, respectively). Cox regression analysis demonstrated that time to ACT initiation (early vs. late, HR = 0.486, P = 0.008) was independently associated with OS.

CONCLUSION

Early initiation of ACT (<4 weeks) confers a survival benefit, and is an independent prognostic factor of OS in LARC patients following nCRT. Further investigations are needed to define the role of earlier initiation of ACT in patients with LARC after nCRT.

YpN0 rectal cancer patients with sterilized lymph nodes after neoadjuvant chemoradiotherapy are of greater risk of recurrence

BACKGROUND

Indication for adjuvant chemotherapy in ypN0 rectal cancer patients after chemoradiotherapy (CRT) is debated. The clinical significance of the presence of sterilized lymph nodes (LNS) in ypN0 patients remains to be determined.

AIMS

To assess the prognostic value of LNS in ypN0 rectal cancers after neoadjuvant CRT.

METHODS

From 2006-2016, 235 patients underwent TME surgery for non-metastatic mid-low rectal cancer after CRT. A lymph node was considered sterilized if there were signs of treatment response (fibrosis, necrosis or mucus) without residual tumor cells.

RESULTS

180 patients (77%) were classified ypN0 and 55 (23%) ypN+. LNS was present in 20 patients (9%). In ypN0 patients, 5-year OS was similar between patients with and without LNS. In contrast, 5-year DFS was significantly lower in ypN0/LNS + patients (58% vs. 78%, p = 0.043) and was similar to those staged ypN+. In multivariate analysis, two factors were independent predictors of DFS: mesorectal grading (OR = 3.14; 95%CI: 1.10-8.34; p = 0.033) and the presence of LNS (OR = 3.93, 95% CI: 1.06-11.81, p = 0.042) CONCLUSION: The presence of LNS in ypN0 rectal cancer after neoadjuvant CRT is associated with an increased risk of recurrence and may be taken into account for the discussion of adjuvant chemotherapy.

Prognostic value of tumour-infiltrating CD8+ lymphocytes in rectal cancer after neoadjuvant chemoradiation: is indoleamine-2,3-dioxygenase (IDO1) a friend or foe?

The prognostic value of the local immune phenotype in patients with colorectal cancer has been extensively studied. Neoadjuvant radiotherapy and/or chemotherapy may potentially influence these immune responses. In this study, we examined the prognostic role of indoleamine-2,3-Dioxygenase (IDO1) and infiltrating cytotoxic T lymphocytes (CD8+) in locally advanced rectal carcinomas after neoadjuvant treatment. Expression of IDO1 and CD8 was evaluated by immunohistochemistry in 106 archival tumour tissue samples from patients following neoadjuvant chemoradiation and radical resection. The average infiltration of IDO1+ and CD8+ cells was calculated along the tumour invasive front, in the tumour centre and within the neoplastic cells and expressed as total scores. Of the tumour specimens evaluable for immunohistochemistry, 100% showed CD8+ lymphocyte infiltration and 93.4% stained positive for IDO1. Total IDO1 score positively correlated with total CD8 score for all three subsites (p = 0.002, Kendall-tau-b 0.357). A high total CD8 score was positively correlated with lower ypUICC-stages (p = 0.047) and lower ypT-categories (p = 0.032). Total IDO1 expression showed a clear trend towards a lower risk of recurrence (p = 0.078). A high total IDO1 score was an independent prognostic marker for prolonged disease-free survival (HR 0.38, p = 0.046) and a high total CD8 score for favourable overall survival (HR 0.16, p = 0.029). Analysis of the local CD8 and IDO1 expression profile may be a helpful tool in predicting prognosis for patients with locally advanced rectal cancer following neoadjuvant chemoradiation.

Cost-utility analysis of 5-fluorouracil and capecitabine for adjuvant treatment in locally advanced rectal cancer

Background

Adjuvant chemotherapy at concurrent time with radiation therapy (RT) or at adjuvant time alone in locally advanced rectal cancer (LARC) is used with several regimens. The cost-utility analysis was conducted to compare administration of two 5-FU regimens and capecitabine in the aspect of provider and societal viewpoint.

Methods

Stage II or III rectal cancer patients who received pre-operative or post-operative concurrent chemoradiotherapy and adjuvant chemotherapy were compared by using decision tree model between (I) 5-FU plus leucovorin (LV) for 5 days per cycle (Mayo Clinic regimen); (II) 5-FU continuous infusion (CI) for 120-h per cycle (CAO/ARO/AIO-94 protocol); (III) standard regimen of capecitabine. All probability data were extracted from landmark study. Direct medical costs were the cost from database of Drug Medical Supply Information Center, while direct non-medical cost and utility were interviewed from stage II and III rectal cancer patients. The time horizon of this study was 5 years. Incremental cost-effectiveness ratio (ICER) was the final result in this study, which determined as the numerator of the difference of costs among three drug regimens, and the difference of quality-adjusted life years (QALYs) from each drug was the denominator.

Results

5-FU plus LV was the cheapest and least efficacy for adjuvant treatment of LARC in both provider and societal viewpoint. In provider viewpoint, the ICERs of 5-FU CI and capecitabine were 334,550 THB/QALY (US $9,840/QALY) and 189,935 THB/QALY (US $5,586/QALY), respectively, with the corresponding societal viewpoint of 264,447 THB/QALY (US $7,778/QALY) and 119,120 THB/QALY (US $3,504/QALY) when 5-FU plus LV was used as comparator. The most influential parameter for value of treatment was acquisition cost of capecitabine. At the willingness to pay for one QALY gained in Thailand (160,000 THB or US $4,706), 5-FU plus LV, 5-FU CI and capecitabine had probabilities of cost-effectiveness of 63%, 2% and 35%, respectively.

Conclusions

Capecitabine was the most expensive regimen but produced the higher effectiveness than 5-FU plus LV and 5-FU CI. The most influential parameter in the model was acquisition cost of capecitabine.

Prognostic significance of neoadjuvant rectal score in locally advanced rectal cancer after neoadjuvant chemoradiotherapy and construction of a prediction model

AIM

To evaluate the prognostic significance of neoadjuvant rectal (NAR) score after neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC), and to develop a nomogram predicting disease-free survival (DFS).

METHOD

A total of 522 LARC patients undergoing nCRT and surgery were included. NAR scores were calculated using the equation [5pN-3(cT-pT) + 12]^2/9.61, and classified as low (<8), intermediate (8-16), and high (>16). Clinicopathological and survival outcomes were compared. Cox regression analysis was performed to identify risk factors of DFS. A predicting nomogram was developed and validated internally.

RESULTS

For NAR score classification, 193 (37.0%) were low, 183 (35.0%) were intermediate, and 146 (28.0%) were high. Higher NAR score was associated with fewer pCR, lower tumor regression grade (TRG), and higher ypTNM stage. A total of 5-year DFS for low, intermediate, and high NAR groups was 85.6%, 71.9%, and 47.2%, respectively (P < 0.001). NAR score (HR = 2.488, P = 0.002), TRG (HR = 2.811, P = 0.047), CRM involvement (HR = 2.703, P = 0.002), and IMA nodal metastasis (HR = 2.441, P = 0.001) were independent prognostic factors of DFS. A predicting nomogram was developed with C-index of 0.701.

CONCLUSION

NAR score could help in predicting DFS after nCRT. A nomogram was developed to identify subpopulations with aggressive tumors during clinical decision-making.

Impact of adjuvant chemotherapy after neoadjuvant radio- or radiochemotherapy for patients with locally advanced rectal cancer

BACKGROUND

Due to its primarily extraperitoneal location, potential affection of the anorectal continence and different metastatic behavior the rectal carcinoma (RC) is classified and treated as an independent disease. Over the past few decades various trials have led to improved multimodal therapies (including radiation, chemotherapy and surgery) for locally advanced rectal cancer and significant changes in the management of this disease whereas the benefit of adjuvant chemotherapy remains unclear.

METHODS

Based on a prospective tumor register of the University Hospital of Wuerzburg data of 263 patients having undergone neoadjuvant therapy and surgical resection for locally advanced rectal cancer were retrieved from the Wuerzburg International database (WID) between October 1992 and September 2013 analyzing the overall survival according to the application of an adjuvant therapy.

RESULTS

The cohort consisted of 263 patients with a median age of 65 years (27-89 years), mostly male gender (n = 191; 72.6%) and an ASA performance score of II or III. 143 patients (54.3%) received an adjuvant therapy. Those patients have been significant younger (median 10 years; p < 0.05) and in a better general condition (ASA-score; p < 0.05). The tumor specific overall survival of adjuvant treated patients was significant better (5-years overall-survival 87.4%; p = 0.025) than the surveillance group. In the performed subgroup analysis no significant differences in overall survival according to the kind of neoadjuvant therapy (radiation vs. radiochemotherapy) have been found whereas patients in lower UICC-stages (ypUICC 0 + I) had a significant benefit by receiving a postoperative chemotherapy (p = 0.035).

CONCLUSION

We considered patients with locally advanced rectal cancer have a significant benefit in overall survival by receiving an adjuvant chemotherapy especially in lower pathological tumor stage (ypUICC 0 + I). Especially because of the heterogeneity of our study population prospective randomized trials are necessary to determine the impact of adjuvant chemotherapy for locally advanced rectal cancer.