Neoadjuvant chemotherapy prior to preoperative chemoradiation or radiation in rectal cancer: should we be more cautious?

Neoadjuvant chemotherapy (NACT) is a term originally used to describe the administration of chemotherapy preoperatively before surgery. The original rationale for administering NACT or so-called induction chemotherapy to shrink or downstage a locally advanced tumour, and thereby facilitate more effective local treatment with surgery or radiotherapy, has been extended with the introduction of more effective combinations of chemotherapy to include reducing the risks of metastatic disease. It seems logical that survival could be lengthened, or organ preservation rates increased in resectable tumours by NACT. In rectal cancer NACT is being increasingly used in locally advanced and nonmetastatic unresectable tumours. Randomised studies in advanced colorectal cancer show high response rates to combination cytotoxic therapy. This evidence of efficacy coupled with the introduction of novel molecular targeted therapies (such as Bevacizumab and Cetuximab), and long waiting times for radiotherapy have rekindled an interest in delivering NACT in locally advanced rectal cancer. In contrast, this enthusiasm is currently waning in other sites such as head and neck and nasopharynx cancer where traditionally NACT has been used. So, is NACT in rectal cancer a real advance or just history repeating itself? In this review, we aimed to explore the advantages and disadvantages of the separate approaches of neoadjuvant, concurrent and consolidation chemotherapy in locally advanced rectal cancer, drawing on theoretical principles, preclinical studies and clinical experience both in rectal cancer and other disease sites. Neoadjuvant chemotherapy may improve outcome in terms of disease-free or overall survival in selected groups in some disease sites, but this strategy has not been shown to be associated with better outcomes than postoperative adjuvant chemotherapy. In particular, there is insufficient data in rectal cancer. The evidence for benefit is strongest when NACT is administered before surgical resection. In contrast, the data in favour of NACT before radiation or chemoradiation (CRT) is inconclusive, despite the suggestion that response to induction chemotherapy can predict response to subsequent radiotherapy. The observation that spectacular responses to chemotherapy before radical radiotherapy did not result in improved survival, was noted 25 years ago. However, multiple trials in head and neck cancer, nasopharyngeal cancer, non-small-cell lung cancer, small-cell lung cancer and cervical cancer do not support the routine use of NACT either as an alternative, or as additional benefit to CRT. The addition of NACT does not appear to enhance local control over concurrent CRT or radiotherapy alone. Neoadjuvant chemotherapy before CRT or radiation should be used with caution, and only in the context of clinical trials. The evidence base suggests that concurrent CRT with early positioning of radiotherapy appears the best option for patients with locally advanced rectal cancer and in all disease sites where radiation is the primary local therapy.     

Gene polymorphisms predict toxicity to neoadjuvant therapy in patients with rectal cancer

BACKGROUND

Toxicity from neoadjuvant chemoradiation therapy (NT) increases morbidity and limits therapeutic efficacy in patients with rectal cancer. The objective of this study was to determine whether specific polymorphisms in genes associated with rectal cancer response to NT were correlated with NT‐related toxicity.

METHODS

One hundred thirty‐two patients with locally advanced rectal cancer received NT followed by surgery. All patients received 5‐fluorouracil (5‐FU) and radiation (RT), and 80 patients also received modified infusional 5‐FU, folinic acid, and oxaliplatin chemotherapy (mFOLFOX‐6). Grade ≥3 adverse events (AEs) that occurred during 5‐FU/RT and during combined 5‐FU/RT + mFOLFOX‐6 were recorded. Pretreatment biopsy specimens and normal rectal tissues were collected from all patients. DNA was extracted and screened for 22 polymorphisms in 17 genes that have been associated with response to NT. Polymorphisms were correlated with treatment‐related grade ≥3 AEs.

RESULTS

Overall, 27 of 132 patients (20%) had grade ≥3 AEs; 18 patients had a complication associated only with 5‐FU/RT, 3 patients experienced toxicity only during mFOLFOX‐6, and 6 patients had grade ≥3 AEs associated with both treatments before surgery. Polymorphisms in the genes x‐ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), xeroderma pigmentosum group D (XPD), and tumor protein 53 (TP53) were associated with grade ≥3 AEs during NT (P < .05). Specifically, 2 polymorphisms—an arginine‐to‐glutamine substitution at codon 399 (Q399R) in XRCC1 and a lysine‐to‐glutamine substitution at codon 751 (K751Q) in XPD—were associated with increased toxicity to 5‐FU/RT (P < .05), and an arginine‐to‐proline substitution at codon 72 (R72P) in TP53 was associated with increased toxicity to mFOLFOX‐6 (P = .008).

CONCLUSIONS

Specific polymorphisms in XRCC1, XPD, and TP53 were associated with increased toxicity to NT in patients with rectal cancer. The current results indicated that polymorphism screening may help tailor treatment for patients by selecting therapies with the lowest risk of toxicity, thus increasing patient compliance. Cancer 2013. © 2012 American Cancer Society.     

新辅助放化疗后低位直肠癌术后吻合口漏危险因素分析

目的:探讨接受新辅助放化疗的患者行腹腔镜直肠癌低位前切除术(low anterior resection,LAR)术后发生吻合口漏的危险因素.方法:采用回顾性病例对照研究方法.收集2010年01月至2019年12月南通大学附属东台医院、苏州大学附属第一医院收治的146例cT3-4期和(或)N1-2期低位直肠癌患者临床资...     

Improved incidence of pT0 downstaged surgical specimens in locally advanced rectal cancer (LARC) treated with induction oxaliplatin plus 5-fluorouracil and preoperative chemoradiation.

PURPOSE: To compare efficacy in terms of pathologic response in LARC patients treated with preoperative chemoradiation, with or without a short-intense course of induction oxaliplatin. PATIENTS AND METHODS: From 05/98 to 10/02, 114 patients were treated with preoperative chemoradiation (4500-5040 cGy + oral Tegafur 1200 mg/day) for cT(3)-(4)N(+/x)M(0) rectal cancer. Starting 05/01, 52 consecutive patients additionally received induction FOLFOX-4, oxaliplatin (85 mg/m(2) iv d1), 5-FU (400 mg/m(2) iv bolus d1) and 600 mg/m(2) iv continuous infusion in 22 h with leucovorin (200 mg iv) d1 and d2, every 15 days (2 cycles), followed by the previously described Tegafur chemoradiation regime. Surgery was performed in 5-6 weeks. Pathological assessment investigated post-treatment T and N status in the rectal wall and peri-rectal tissues. RESULTS: Patients, tumor and treatment characteristics were comparable between groups. Incidence of pT(0) specimens was significantly increased by induction FOLFOX-4 (P = 0.006). Total T and N downstaging were 58% versus 75% and 42% versus 40%, respectively (P = ns). T downstaging of > or =2 categories was significantly superior in FOLFOX-4 group (P = 0.029). CONCLUSIONS: Short-intense induction FOLFOX-4 significantly improves pathologic complete response in LARC patients treated with tegafur-sensitized preoperative chemoradiation. The 44% rate of pT(0)-(1) specimens observed in the oxaliplatin group should impulse innovative surgical approaches to promote ano-rectal sphincter conserving protocols.     

Preoperative downstaging chemoradiation with concurrent irinotecan and capecitabine in MRI-defined locally advanced rectal cancer: a phase I trial (NWCOG-2)

Background:

The aim of this study was to investigate the safety of neoadjuvant chemoradiation using radiotherapy (RT) combined with concurrent capecitabine and irinotecan for locally advanced rectal cancer before surgery.

Methods:

Forty-six patients were recruited and treated on the basis that MRI scanning had shown poor-risk tumours with threatening (⩽1 mm) or involvement of the mesorectal fascia. Conformal RT was given using 3 or 4 fields at daily fractions of 1.8 Gy on 5 days per week to a total dose of 45 Gy. Concurrently oral capecitabine was given twice daily throughout radiotherapy continuously from days 1 to 35 and intravenous irinotecan was given once per week during weeks 1 to 4 of RT. Dose levels were gradually escalated as follows. Dose level 1: capecitabine 650 mg m⁻² b.i.d. and irinotecan 50 mg m⁻²; Dose level 2: capecitabine 650 mg m⁻² b.i.d. and irinotecan 60 mg m⁻²; Dose level 3: capecitabine 825 mg m⁻² b.i.d. and irinotecan 60 mg m²; Dose level 4: capecitabine 825 mg m⁻² b.i.d. and irinotecan 70 mg m⁻².

Results:

Diarrhoea (grade 3, no grade 4) was the main serious acute toxicity with lesser degrees of fatigue, neutropenia, anorexia and palmar-plantar erythrodysesthesia. The recommended dose for future study was dose level 2 at which 3 of 14 patients (21%) developed grade 3 diarrhoea. Postoperative complications included seven pelvic or wound infections and two anastomotic and two perineal wound dehiscences. There were no deaths in the first 30 days postoperatively. Of 41 resected specimens, 11 (27%) showed a pathological complete response (pCR) and five (12%) showed an involved circumferential resection margin (defined as ⩽1 mm). The 3-year disease-free survival (intent-to-treat) was 53.2%.

Conclusion:

In patients with poor-risk MRI-defined locally advanced rectal cancer threatening or involving the mesorectal fascia, preoperative chemoradiation based on RT at 45 Gy in 25 daily fractions over 5 weeks with continuous daily oral capecitabine at 650 mg m⁻² b.i.d. days 1–35 and weekly IV irinotecan at 60 mg m⁻² weeks 1–4, provides acceptable acute toxicity and postoperative morbidity with encouraging response and curative resection rates.     

直肠癌术前放化疗完全缓解后的临床策略分析

  目的  探讨直肠癌经新辅助放化疗后获得完全缓解病例的处理办法。  方法  回顾性分析河南大学淮河医院2010年1月至2014年8月收治的直肠癌术前进行新辅助放化疗的84例患者临床资料。  结果  经过新辅助放化疗,33例（39.3%）患者获得临完全床缓解（clinical complete response,cCR）;经术后病理检查,6例患者获得病理完全缓解（pathological complete response,pCR）,占cCR病例的18.2%（6/33）,术后随访12~36个月均未出现肿瘤转移复发情况。  结论  新辅助放化疗能明显降低肿瘤分期,并能使部分患者获得cCR。对于cCR病例,不建议非手术治疗。      

Methylenetetrahydrofolate reductase genetic polymorphisms and toxicity to 5-FU-based chemoradiation in rectal cancer

Background:

There is a large degree of variation in tumour response and host toxicities associated with neoadjuvant chemoradiation for rectal cancer patients. We performed a complimentary pharmacogenetic study to investigate germline polymorphisms of genes involved in 5-fluorouracil (5-FU) and irinotecan pathways and their potential association with clinical outcomes and toxicities from neoadjuvant chemoradiation in patients with rectal cancer treated in a prospective genotype-directed study.

Methods:

The germline DNA of 131 patients was genotyped for 10 variants in TYMS, MTHFR, DPYD, UGT1A1, ABCC1 and SLCO1B1 genes. Ninety-six patients were treated with 5-FU/radiotherapy (RT) and 35 received 5-FU/RT/irinotecan. Relationships between genetic variants and adverse events, tumour response, overall and disease-free survivals were assessed.

Results:

MTHFR 1298A>C and MTHFR diplotypes (for 677C>T and 1298A>C) were associated with chemoradiation-related toxicity when 5-FU was used alone. MTHFR haplotypes (677C–1298C) and diplotypes (CA–TA and TA–TA) showed, respectively, a protective and a negative effect on the incidence of severe diarrhoea or mucositis. No association was observed between genetic markers and drug response.

Conclusion:

MTHFR polymorphisms can potentially predict toxicity in patients treated with 5-FU as a single chemotherapeutic drug.     

直肠癌的新辅助治疗

为了保留肛门、减少复发、延长生存,新辅助化放疗已成为直肠癌治疗的重要组成部分.本文详细论述了直肠癌新辅助治疗的发展和现状.探讨了新辅助放疗、新辅助放化疗与单纯手术及辅助化放疗相比的优劣.     

Phase 2 study of preoperative radiation with concurrent capecitabine,oxaliplatin, and bevacizumab followed by surgery and postoperative 5‐fluorouracil,leucovorin, oxaliplatin (FOLFOX), and bevacizumab in patients with locally advanced rectal cancer: ECOG 3204

BACKGROUND:

Recent studies have demonstrated the feasibility of combining oxaliplatin with 5‐fluorouracil (5‐FU) or capecitibine and radiation therapy. The addition of bevacizumab to chemotherapy improves overall survival for metastatic disease. We initiated a phase 2 trial to evaluate preoperative capecitabine, oxaliplatin, and bevacizumab with radiation therapy followed by surgery and postoperative 5‐FU, leucovorin, oxaliplatin (FOLFOX) and bevacizumab for locally advanced rectal cancer.

METHODS:

Fifty‐seven patients with resectable T3/T4 rectal adenocarcinoma were enrolled. Preoperative treatment was capecitabine (825 mg/m² twice daily from Monday to Friday), oxaliplatin (50 mg/m² weekly), bevacizumab (5 mg/kg on days 1, 15, 29), and radiation therapy (50.4 Gy). Surgery was performed by 6 weeks after neoadjuvant therapy. Beginning 8 to 12 weeks after surgery, patients received FOLFOX plus bevacizumab (5 mg/kg) every 2 weeks for 12 cycles.

RESULTS:

Fifty‐four of 57 enrolled patients were eligible. Forty‐nine (91%) patients completed preoperative therapy and underwent surgery. Nine patients (17%; 90% confidence interval, 9%‐27%) achieved pathologic complete response. Thirty‐two patients (59%) experienced pathologic tumor downstaging, and 53% and 15% of patients experienced worst grade 3 and grade 4 acute toxicity, respectively. Forty‐seven percent of patients who underwent surgery experienced a surgical complication.

CONCLUSIONS:

The primary endpoint of a 30% pathologic complete response rate was not reached; however, the majority of patients experienced pathologic downstaging with this regimen. Increased wound‐healing delays and complications may have been related to the addition of bevacizumab, oxaliplatin, or both. Continued observation of these patients will establish the long‐term morbidity and efficacy of this combined modality approach. Cancer 2013. © 2012 American Cancer Society.     

新辅助治疗——对直肠癌现有治疗模式的挑战?

近年来,新辅助治疗对于直肠癌的疗效得到进一步的肯定,已被公认为进展期直肠癌的标准治疗方法。一些研究甚至开始探讨新辅助治疗是否可以取代根治性手术成为主导治疗方式。放化疗后临床分期的准确度以及T分期与淋巴结阳性率的相关性这两个方面从理论上决定非根治性手术的可行性。尽管目前不乏新辅助治疗后不手术或行局部切除术结果满意的报告,但由于缺乏前瞻性研究,关于新辅助治疗在进展期直肠癌治疗中的地位仍存在争议。     

Intensified concurrent chemoradiotherapy with 5-fluorouracil and irinotecan as neoadjuvant treatment in patients with locally advanced rectal cancer

This study aimed to evaluate the feasibility and efficacy of neoadjuvant chemoradiotherapy intensified with irinotecan in patients with locally advanced rectal cancer. Eligible patients had nonmetastatic disease at a locally advanced stage that made R0 resection and sphincter preservation uncertain. They received preoperative radiation over 6 weeks to 45 Gy and boost of 5.4 Gy and concurrent continuous infusion 5-fluorouracil 250 mg m(-2) day(-1) and weekly irinotecan 40 mg m(-2). In all, 37 patients entered the study. T stage at baseline as determined by ultrasound was T2/T3/T4 in 2/19/16 patients; 31 patients had lymph node involvement. The predominant toxicity was diarrhoea (grade 3/4 in 10/2 patients). Haematologic toxicity and surgical complications were moderate. Among 36 patients undergoing surgery, 32 (89%) had R0 resection and 23 (64%) sphincter preservation. Pathologic complete response (pCR) was achieved in eight (22%) of 36 patients, and 10 patients (28%) had only microscopic residual disease. At 4 years, overall survival was 66%, disease-free survival 73%, local relapse rate 7%, and distant failure rate 24%. Extent of resection and postoperative nodal status were significant predictors of overall and disease-free survival. Intensified neoadjuvant chemoradiotherapy with irinotecan can be safely administered and results in a high pCR rate.