Predictive factors of tumor response after neoadjuvant chemoradiation for locally advanced rectal cancer

Post-chemoradiation anastomotic recurrence in locally advanced rectal cancer: no increased risk associated with distal margin

BACKGROUND AND PURPOSE

Anastomotic recurrence after radical sphincter-preserving surgery preceded by neoadjuvant therapy in locally advanced rectal cancer is an uncommon event that merits further assessment. The aim of this study is to analyze the effect of preoperative chemoradiation on the risk of anastomotic recurrence. Based on the initial extension of the tumor, we analyzed whether the distal surgical section was calculated through the virtual initial extension of the rectal tumor.

PATIENTS AND METHODS

Eligible patients with locally advanced rectal cancer were offered preoperative chemoradiation, sphincter sparing surgery and intraoperative radiation therapy boost.

RESULTS

180 patients were treated with anterior resection (40 %), low anterior resection (45.6 %) and ultra-low anterior resection (14.4 %). With a median follow-up of 41.1 months (0.36-143 months), anastomotic recurrence was diagnosed in 9 patients (5 %). There was no statistical correlation with downstaging (T or N), downsizing effects, or with distance from the lower limit of the residual lesion to the distal margin. Virtual intratumoral surgical section was speculated in 44 patients (3 developed anastomotic recurrence; 6.8 vs 4.8 %, p = 0.482).

CONCLUSION

Anastomotic recurrence in patients with rectal cancer treated with neoadjuvant chemoradiation is an infrequent event. Virtual intratumoral surgical sections followed by anastomosis do not contribute to an excessive risk of recurrence. Our findings encourage the development of policies for preservation of the ano-rectal complex in rectal cancer patients.

Prognostic significance of serum carcinoembryonic antigen normalization on survival in rectal cancer treated with preoperative chemoradiation

PURPOSE

The purpose of this retrospective study was to identify factors predictive of survival in rectal cancer patients who received surgery with curative intent after preoperative chemoradiotherapy (CRT).

MATERIALS AND METHODS

Between July 1996 and June 2010, 104 patients underwent surgery for rectal cancer after preoperative CRT. The median dose of radiotherapy was 50.4 Gy (range, 43.2 to 54.4 Gy) for 6 weeks. Chemotherapy was a bolus injection of 5-fluorouracil and leucovorin for the first and last week of radiotherapy (n=84, 77.1%) or capecitabine administered daily during radiotherapy (n=17, 16.3%). Low anterior resection (n=86, 82.7%) or abdominoperineal resection (n=18, 17.3%) was performed at a median 47 days from the end of radiotherapy, and four cycles of adjuvant chemotherapy was administered. The serum carcinoembryonic antigen (CEA) level was checked at initial diagnosis and just before surgery.

RESULTS

After a median follow-up of 48 months (range, 9 to 174 months), 5-year disease free survival (DFS) was 74.5% and 5-year overall survival (OS) was 86.4%. Down staging of T diagnoses occurred in 32 patients (30.8%) and of N diagnoses in 40 patients (38.5%). The CEA change from initial diagnosis to pre-surgery (high-high vs. high-normal vs. normal-normal) was a statistically significant prognostic factor for DFS (p=0.012), OS (p=0.002), and distant metastasis free survival (p=0.018) in a multivariate analysis.

CONCLUSION

Patients who achieve normal CEA level by the time of surgery have a more favorable outcome than those who retain a high CEA level after preoperative CRT. The normalization of CEA levels can provide important information about the prognosis in rectal cancer treatment.

Future directions in combined modality therapy for rectal cancer: reevaluating the role of total mesorectal excision after chemoradiotherapy

Most patients who develop rectal cancer present with locoregionally advanced (T3 or node-positive) disease. The standard management of locoregionally advanced rectal cancer is neoadjuvant concurrent chemoradiotherapy (nCRT), followed by radical resection (low-anterior resection or abdominoperineal resection with total mesorectal excision). Approximately 15% of patients can have a pathologic complete response (pCR) at the time of surgery, indicating that some patients can have no detectable residual disease after nCRT. The actual benefit of surgery in this group of patients is unclear. It is possible that omission of surgery in these patients, termed selective nonoperative management, can limit the toxicities associated with standard, multimodal combined modality therapy without compromising disease control. In this review, we discuss the clinical experiences to date using selective nonoperative management and various attempts at escalation of nCRT to improve the number of patients who have a pCR. We also explore several clinical, laboratory, imaging, histopathologic, and genetic biomarkers that have been tested as tools to predict which patients are most likely to have a pCR after nCRT.

Existem benefícios com a cirurgia retardada após radioterapia e quimioterapia neoadjuvante no câncer de reto localmente avançado?

RACIONAL: Tratamento neoadjuvante com radioterapia e quimioterapia é o esquema preferencial para câncer de reto localmente avançado, tendo por objetivo aumentar a ressecabilidade e diminuir a recidiva local. OBJETIVO: Avaliar os benefícios da operação tardia após radioterapia e quimioterapia neoadjuvante em câncer de reto localmente avançado quanto à resposta da regressão tumoral, sobrevida e efeitos adversos. MÉTODOS: Foram tratados consecutivamente 106 pacientes, portadores de adenocarcinoma do reto localmente avançado no período pré-operatório com radioterapia na dose de 50,4 Gy (28 frações) e quimioterapia com 5-fluoracil e leucovorin. A operação foi programada entre cinco e seis semanas. Pacientes que retornaram após seis semanas por motivos diversos foram agrupados em grupo de operação tardia. Variáveis como diminuição do estádio, remissão tumoral completa, tempo cirúrgico, transfusão sanguínea, recidiva local, metástase e sobrevida foram correlacionadas com o restante dos pacientes a fim de verificar os seus benefícios. RESULTADOS: Remissão completa do tumor foi encontrada em 15 pacientes (T0=15/106 - 14,2%). Resposta parcial em 38 (34,9%); entretanto em um paciente a resposta foi pT0N2. O seguimento médio foi 35,6 semanas e 32,2 semanas para grupo de operação em seis semanas e grupo de cirurgia tardia. Não houve diferença entre os dois grupos quanto à diminuição de estádio, remissão tumoral completa, tempo cirúrgico, transfusão sanguínea e complicações cirúrgicas precoces. Embora a operação tardia não apresentasse diferença significante quanto à recidiva local (p=0,1468), ela mostrou tendência em menor risco de metástase à distância (p=0,0520). CONCLUSÃO: Operação tardia após tratamento neoadjuvante não oferece benefícios evidentes em termos de remissão completa ou diminuição do estádio tumoral. Fatores moleculares preditivos devem ser investigados no futuro para melhor seleção de doentes que poderão beneficiar-se com o tratamento neoadjuvante.

Response to neoadjuvant therapy in patients with early age-of-onset rectal cancer

BACKGROUND

The incidence of rectal cancer in patients ≤ 50 years of age is increasing. The response to neoadjuvant treatment in patients ≤ 50 years of age is not known. Factors affecting the response to neoadjuvant therapy in this age group have not been evaluated.

OBJECTIVE

This study aims to evaluate the rate and identify factors that affect pathologic response to neoadjuvant therapy in patients with early age-of-onset rectal cancer.

DESIGN

This study is a retrospective review.

SETTING

The investigation was conducted at a tertiary-care cancer referral center.

PATIENTS

Included were 193 consecutive patients ≤ 50 years of age with rectal cancer who underwent neoadjuvant therapy followed by surgical resection.

INTERVENTIONS

No interventions were performed.

MAIN OUTCOME MEASURES

The primary outcome measured was the pathologic response to neoadjuvant treatment.

RESULTS

The median age was 44 years, and 34% of the patients were female. The median distance from the anal verge was 7 cm. The median percentage of lumen occupied by tumor was 50%. The median CEA level was 3.5 ng/mL. The median treatment response was 80%. The mean number of lymph nodes examined was 15 per patient. Twenty-two percent of patients had a complete or near-complete (≥ 95%) response to neoadjuvant treatment. Seventy-seven percent of evaluable patients experienced tumor or lymph node downstaging on pathologic examination. The presence of adverse histologic features, percentage of lumen occupied by tumor, and CEA level differed between those with <95% response and those with ≥ 95% response to neoadjuvant therapy, although CEA level was not significant when stage IV patients were excluded.

LIMITATIONS

This is a retrospective review with heterogeneity in workup, treatment regimens, and interval to surgery. Long-term oncologic outcomes are not available.

CONCLUSIONS

The rate of response to neoadjuvant treatment appears similar in patients with early age-of-onset rectal cancer to non-age-based cohorts in the literature. Adverse histologic features and bulky circumferential tumors may be suggestive of a decreased response to neoadjuvant therapy.

Treatment of locally advanced rectal cancer: Controversies and questions

Rectal cancers extending through the rectal wall, or involving locoregional lymph nodes (T3/4 or N1/2), have been more difficult to cure. The confines of the bony pelvis and the necessity of preserving the autonomic nerves makes surgical extirpation challenging, which accounts for the high rates of local and distant relapse in this setting. Combined multimodality treatment for rectal cancer stage II and III was recommended from National Institute of Health consensus. Neoadjuvant chemoradiation using fluoropyrimidine-based regimen prior to surgical resection has emerged as the standard of care in the United States. Optimal time of surgery after neoadjuvant treatment remained unclear and prospective randomized controlled trial is ongoing. Traditionally, 6-8 wk waiting period was commonly used. The accuracy of studies attempting to determine tumor complete response remains problematic. Currently, surgery remains the standard of care for rectal cancer patients following neoadjuvant chemoradiation, whereas observational management is still investigational. In this article, we outline trends and controversies associated with optimal pre-treatment staging, neoadjuvant therapies, surgery, and adjuvant therapy.

Elevated CEA levels and low distance of the tumor from the anal verge are predictors of incomplete response to chemoradiation in patients with rectal cancer

BACKGROUND

The objective of this study was to evaluate pretreatment clinical parameters as predictive factors for complete pathological response after long-term chemoradiotherapy (RCT) for rectal cancer. Tumor downstaging after RCT for rectal cancer can be obtained in half of cases, whereas a complete pathological response (CPR) is reported to range between 15 and 30%. It is not possible to foresee before therapies who will respond.

METHODS

Patients with stage II-III rectal cancer that had undergone RCT and rectal resection between January 1995 and October 2010 were considered. Patients were divided in those who achieved a CPR, "CR" group, and those who did not achieve a CPR, "NCR" group. Univariate and multivariate analyses between groups were performed considering the clinical parameters: gender, age, ASA score, preoperative hematic CEA, tumor grading; distance of the tumor from the anal verge, maximum tumor diameter, TNM stage, and neoadjuvant treatment details.

RESULTS

Among 260 patients, 43 (16.5%) achieved a CPR. The two groups resulted homogeneous for age, sex, pretreatment status, and tumor stage. A CEA <5 ng/dl and distance from anal verge >5 cm were correlated with CPR at multivariate analysis. Patients with both these conditions presented a significantly higher CPR rate (30.6%) as well as improved 5-year survival. CPR was also correlated with improved survival.

CONCLUSIONS

Very low tumors with a high serum CEA are very unlikely to reach a CPR. The predictive value of these easily available clinical factors should not be underestimated, and better therapeutic strategies for these tumors are needed.

Predictive factors of the response of rectal cancer to neoadjuvant radiochemotherapy

Locally advanced rectal cancer is currently treated with pre-operative radiochemotherapy (pRCT), but the response is not uniform. Identification of patients with higher likelihood of responding to pRCT is clinically relevant, as patients with resistant tumors could be spared exposure to radiation or DNA-damaging drugs that are associated with adverse side effects. To highlight predictive biomarkers of response to pRCT, a systematic search of PubMed was conducted with a combination of the following terms: "rectal", "predictive", "radiochemotherapy", "neoadjuvant", "response" and "biomarkers". Genetic polymorphisms in epithelial growth factor receptor (EGFR) and thymidylate synthase (TS) genes, the expression of several markers, such as EGFR, bcl-2/bax and cyclooxygenase (COX)-2, and circulating biomarkers, such as serum carcinoembryonic antigen (CEA) level, are promising as predictor markers, but need to be further evaluated. The majority of the studies did not support the predictive value of p53, while the values of Ki-67, TS and p21 is still controversial. Gene expression profiles of thousands of genes using microarrays, microRNA studies and the search for new circulating molecules, such as human telomerase reverse transcriptase mRNA and cell-free DNA, are providing interesting results that might lead to the identification of new useful biomarkers. Evaluation of biomarkers in larger, prospective trials are required to guide therapeutic strategies.