Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

Pathologic stage is most prognostic of disease-free survival in locally advanced rectal cancer patients after preoperative chemoradiation

BACKGROUND

Preoperative chemoradiation is the standard treatment for locally advanced rectal cancer. However, it is uncertain whether pretreatment clinical stage, degree of response to neoadjuvant treatment, or pathologic stage is the most reliable predictor of outcome. This study compared various staging elements and treatment-related variables to identify which factors or combination of factors reliably prognosticates disease-free survival in rectal cancer patients receiving neoadjuvant combined modality therapy.

METHODS

From a prospectively maintained single institution database, 342 consecutive patients with locally advanced rectal cancer staged by endorectal ultrasound were identified. Patients underwent rectal resection 4 to 8 weeks after a 5.5-week course of pelvic radiotherapy/concurrent chemotherapy. The degree of tumor regression was histologically graded on each resected specimen using a previously reported response scale of 0% to 100%. Predictive models of disease-free survival were created utilizing available pretherapy and postoperative staging elements in addition to the degree of tumor regression noted histologically. Model accuracy was measured and compared by concordance index, with 95% confidence interval (CI).

RESULTS

Stratifying patients by degree of tumor regression predicted outcome with a concordance index of 0.65 (95% CI, 0.59-0.71), which was significantly better than models using preoperative stage elements (concordance index of 0.54; 95% CI, 0.50-0.58). However, the model found to be most predictive of disease-free survival stratified patients by final pathologic T classification and N classification elements, with a concordance index of 0.75 (95% CI, 0.70-0.80).

CONCLUSIONS

Tumor response to preoperative therapy is a strong predictor of disease-free survival. However, outcome is most accurately estimated by final pathologic stage, which is influenced by both preoperative stage and response to therapy.

Pathologic response assessed by Mandard grade is a better prognostic factor than down staging for disease-free survival after preoperative radiochemotherapy for advanced rectal cancer

OBJECTIVE

The reduction in tumour stage induced by full course radiotherapy plus chemotherapy is apparent from histological changes. The purpose of this study was to determine the rate of complete pathological response and to evaluate the prognostic value for disease free survival (DFS) and disease specific survival (DSS) of the response. The relation between pretreatment variables (age, gender, stage, tumour height and [carcinoembryogenic antigen (CEA)] and postsurgical variables was compared to the pathological response.

METHOD

A total of 119 patients with stage II or III rectal cancer underwent surgery 6 weeks after neoadjuvant treatment. Group A included patients with a complete or good pathological response (Mandard grade I-II) and group B patients with a poor response (Mandard grade III-IV-V). The pretreatment endo-rectal ultrasound scan stage was compared with histopathology stage of the resected specimen. DFS and DSS were compared using the log-rank test.

RESULTS

All 119 patients (mean age 67.9 years, 83 males) underwent resection. The tumour was located in the upper, middle and lower third of the rectum in 11, 51 and 57 patients. 88 patients had a low anterior resection, 28 patients abdomino-perineal resection and three a Hartmann's operation. There was no postoperative death. The circumferential margin (CM) was involved in 10%. A complete pathological response was observed in 17 (14.2%) patients. Thirty-six (30.2%) patients had a group A and 83 a group B response. Group A showed DFS to be significantly higher than group B (log rank: P = 0.007). The DSS rate was not significantly different between the two groups (log rank P = 0.113). Down-staging was not related with DFS. No relation was found between pretreatment variables and response. A good pathological response was related to a lower rate of permanent colostomy but not with CM involvement or the number of lymph nodes.

CONCLUSION

Tumour regression of grades I or II was a good indicator of DFS in locally advanced rectal cancer, treated by neoadjuvant chemotherapy and radiotherapy. Patients with a high regression grade were associated with a lower incidence of definitive stoma formation. The regression grade was shown to be a better prognostic factor than down-staging.

Circulating lymphangiogenic growth factors in gastrointestinal solid tumors, could they be of any clinical significance?

Metastasis is the principal cause of cancer mortality, with the lymphatic system being the first route of tumor dissemination. The glycoproteins VEGF-C and VEGF-D are members of the vascular endothelial growth factor (VEGF) family, whose role has been recently recognized as lymphatic system regulators during embryogenesis and in pathological processes such as inflammation, lymphatic system disorders and malignant tumor metastasis. They are ligands for the VEGFR-3 receptor on the membrane of the lymphatic endothelial cell, resulting in dilatation of existing lymphatic vessels as well as in vegetation of new ones (lymphangiogenesis). Their determination is feasible in the circulating blood by immunoabsorption and in the tissue specimen by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Experimental and clinicopathological studies have linked the VEGF-C, VEGF-D/VEGFR3 axis to lymphatic spread as well as to the clinical outcome in several human solid tumors. The majority of these data are derived from surgical specimens and malignant cell series, rendering their clinical application questionable, due to subjectivity factors and post-treatment quantification. In an effort to overcome these drawbacks, an alternative method of immunodetection of the circulating levels of these molecules has been used in studies on gastric, esophageal and colorectal cancer. Their results denote that quantification of VEGF-C and VEGF-D in blood samples could serve as lymph node metastasis predictive biomarkers and contribute to preoperative staging of gastrointestinal malignancies.

Survival benefits and trends in use of adjuvant therapy among elderly stage II and III rectal cancer patients in the general population

BACKGROUND

This study examined elderly stage II and III rectal cancer patients' adjuvant chemoradiation therapy adherence, trends in adherence over time, and the relation of levels of adherence to mortality.

METHODS

The authors studied 2886 stage II and III rectal cancer patients who had surgical resection and who appeared in 1992-1999 linked SEER-Medicare claims data. The authors compared measures of adjuvant radiation and chemotherapy receipt and completion between stage II and III patients. Adjusted risk of cancer-related 5-year mortality was calculated by multivariate logistic regression for different levels of chemoradiation adherence among stage II and III patients.

RESULTS

Of the 2886 patients, 45.4% received both adjuvant radiation and chemotherapy. Stage III patients were more likely to receive chemoradiation than stage II patients. The receipt of chemoradiation by stage II patients increased significantly from 1992 to 1999. Stage III patients were more likely to complete radiation therapy (96.6%), chemotherapy (68.2%), and both modalities (67.5%) than stage II patients (91.5%, 49.8%, 47.6%, respectively). Only a complete course of both radiation and chemotherapy for both stage II (relative risk [RR] 0.74; 95% CI, 0.54, 0.97) and III (RR 0.80; 95% CI, 0.65, 0.96) decreased the adjusted 5-year cancer mortality risk compared with counterparts with no adjuvant therapy.

CONCLUSIONS

Even though stage II rectal cancer patients were less likely than stage III patients to receive and complete adjuvant chemoradiation, both patient groups in the general population had lower cancer-related mortality if they completed chemoradiation. These patients deserve support and encouragement to complete treatment.

Histopathological response after preoperative radiochemotherapy in rectal carcinoma is associated with improved overall survival

BACKGROUND

Recent studies showed improved local control after preoperative radiochemotherapy (RCTX) in patients with locally advanced rectal carcinoma, but failed to demonstrate a survival benefit. Our aims were to determine outcome and impact of histopathological response after preoperative RCTX.

METHODS

One hundred four patients with uT3 rectal carcinoma were treated with preoperative RCTX of 45 Gy and continuous 5-FU infusion between 1997 and 2001 (group I). Histopathological response was evaluated in all specimens after tumor resection. Group II consisted of 114 patients with uT3 rectal carcinoma treated with postoperative RCTX between 1988 and 1997.

RESULTS

Group I showed a 6.1% 5-year local recurrence rate compared to 15.3% in group II (P = 0.023). Overall survival rates did not differ significantly between both groups (P = 0.225). Histopathological responders had a significantly improved 5-year overall survival with 89.1 (7.8)% compared to 68.7 (6.7)% of the non-responders (P = 0.008) and were identified as an independent prognostic factor.

CONCLUSIONS

Significant improvement of overall survival was observed for histopathological tumor responders after neoadjuvant radiochemotherapy. Our protocol of preoperative radiochemotherapy confirms the results of the multi-center studies in regard to local control and overall survival.

Predictive clinicopathologic factors for limited response of T3 rectal cancer to combined modality therapy

PURPOSE

The response of T3 rectal cancer to combined modality therapy (CMT) is highly predictive of long-term outcome following surgery. The aim of this study was to identify pretreatment factors associated with poor tumor response to neoadjuvant chemoradiation.

METHODS

A prospective institutional database at Memorial Sloan-Kettering Cancer Center was queried for endorectal ultrasound (ERUS) stage T3N0-2 rectal cancer patients, treated with CMT followed by surgical resection, between 1998 and 2003. Preoperative clinicopathologic factors determined by biopsy, ERUS, proctoscopy, and digital rectal examination were correlated with the degree of downstaging of the primary mural lesion (tumor downstaging) in response to neoadjuvant therapy. Associations were analyzed by chi-square, Kaplan-Meier, and logistic regression.

RESULTS

Of 274 patients, 51% obtained tumor downstaging in response to preoperative treatment, i.e., lower pathologic T-stage compared with pretreatment ERUS. Five-year recurrence-free survival was 89% in the cohort that obtained tumor downstaging compared with only 45% in the cohort that obtained no tumor downstaging. Factors significantly associated with limited or lack of tumor downstaging after CMT included: fixed tumor on digital rectal examination (p < 0.021), near-circumferential tumor (p < 0.011), tumor stenosis (p < 0.025), metastatic disease (p < 0.012), biopsy-proven poorly differentiated pathology (p < 0.002), and radial extension >2.5 mm on ERUS (p < 0.031). On multivariate analysis, deep radial extension on ERUS, metastatic disease, and poorly differentiated pathology were in each, independently associated with limited or lack of tumor downstaging.

CONCLUSIONS

Pretreatment evaluation with biopsy, proctoscopy, and ERUS can identify T3 rectal cancer patients unlikely to respond well to CMT. These patients may be considered for alternative protocols and their tumors studied to ascertain the molecular events responsible for resistance to chemoradiation.

Multidisciplinary management of patients with advanced rectal cancer

The chance of lymph node involvement in T(3) and T(4) rectal cancers is 20% to 60%, a risk sufficiently high that most clinicians favor mesorectal excision rather than less aggressive approaches. Patients who have a complete clinical response of the primary lesions to neoadjuvant therapy may represent a special case. Total mesorectal excision can be accomplished without sacrifice of the anal sphincters, and continence can be preserved. Evolving understanding of patterns of tumor spread and mechanisms of anal continence have resulted in increased use of continence-preserving procedures. Removal of the anal sphincters seems to be advantageous only if the sphincters are directly involved. A few small series suggest that a segmental sphincter resection could result in good local control and continence preservation, even if the sphincters are involved. Areas of controversy currently include the role of neoadjuvant therapy for high rectal lesions, the role of lateral lymph node dissection, and methods of improving anal continence after rectal resection.

Phase I-II trial of concurrent capecitabine and oxaliplatin with preoperative intensity-modulated radiotherapy in patients with locally advanced rectal cancer

PURPOSE

To identify the maximal tolerated dose level of preoperative intensity-modulated radiotherapy combined with capecitabine and oxaliplatin and to evaluate the efficacy.

PATIENTS AND METHODS

Patients with rectal T3-T4 and/or N0-N+ rectal cancer received capecitabine 825 mg/m(2) twice daily Monday through Friday and oxaliplatin 60 mg/m(2) intravenously on Days 1, 8, and 15, concurrently with intensity-modulated radiotherapy. The radiation dose was increased in 5.0-Gy steps in cohorts of 3 patients starting from 37.5 Gy in 15 fractions (dose level [DL] 1). DL2 and DL3 were designed to reach 42.5 Gy in 17 fractions and 47.5 Gy in 19 fractions, respectively.

RESULTS

No dose-limiting toxicity was observed at DL1 or DL2. Of the 3 patients treated at DL3, 1 presented with Grade 3 diarrhea, which was considered a dose-limiting toxicity, and 3 additional patients were added. Of the 6 patients treated at DL3, no new dose-limiting toxicities were observed, and DL3 was identified as the recommended dose in this study. Eight additional patients were treated at 47.5 Gy. Grade 2 proctitis was the most frequent adverse event (40%); Grade 3 diarrhea occurred in 2 patients (10%). All patients underwent surgery, and 17 patients (85%) underwent R0 resection. Four patients (20%) presented with a histologic response of Grade 4, 11 (55%) with Grade 3+, 2 (15%) with Grade 3, and 2 patients (10%) with Grade 2.

CONCLUSION

The maximal tolerated dose in this study was 47.5 Gy. The high rates of pathologic response of Grade 3+ and 4 must be confirmed through the accrual of new patients in the Phase II study.

Laparoscopic surgery in rectal cancer: a prospective analysis of patient survival and outcomes

PURPOSE

The role of laparoscopic resection in the management of rectal cancer is still controversial. We prospectively evaluated patient survival and outcomes in patients undergoing laparoscopic rectal resection for rectal cancer at a single institution.

METHODS

From November 1999 to November 2005, 107 patients with rectal cancer were treated by laparoscopy. Exclusion criteria were: metastatic disease, advanced disease with invasion of adjacent structures, clinical or radiologic involvement of the external anal sphincter, previous colonic resection, synchronous colonic adenocarcinoma, and contraindications to laparoscopy. All patients were followed prospectively for survival and complications. Survival was calculated by the Kaplan-Meier method.

RESULTS

A laparoscopic sphincter-saving procedure was performed in 104 patients, 2 patients had a laparoscopic Miles operation, and 1 underwent a laparoscopic Hartmann's procedure. Mean operating time was 278 (range, 135-430) minutes. Conversion to open surgery was required in 20 of 107 patients (18.7 percent). Overall morbidity was 27 percent, anastomotic leakage occurred in 14 of 104 patients (13.5 percent). There was no postoperative mortality. A mean of 18 (range, 1-49) lymph nodes was removed. Mean distance of distal margin from tumor was 2.6 (range, 0.5-10) cm; in two patients there was microscopic invasion of the distal margin. Mean hospital stay was nine (range, 4-43) days. Mean follow-up was 35.8 months. There was local recurrence in 1 of 107 patients (0.95 percent); there were no port site metastases. Actuarial five-year and disease-free survival rates are 81.4 and 79.8 percent, respectively.

CONCLUSIONS

Laparoscopic rectal surgery is feasible and oncologically radical but also technically demanding (conversion rate, 18.7 percent), time-consuming (mean operating time, 278 minutes), and associated with specific intraoperative complications. At present, the technique should only be performed in specialist centers by teams experienced in laparoscopic surgery.

Rectal cancer treatment: Improving the picture

Multidisciplinary approach for rectal cancer treatment is currently well defined. Nevertheless, new and promising advances are enriching the portrait. Since the US NIH Consensus in the early 90’s some new characters have been added. A bird’s-eye view along the last decade shows the main milestones in the development of rectal cancer treatment protocols. New drugs, in combination with radiotherapy are being tested to increase response and tumor control outcomes. However, therapeutic intensity is often associated with toxicity. Thus, innovative strategies are needed to create a better-balanced therapeutic ratio. Molecular targeted therapies and improved technology for delivering radiotherapy respond to the need for accuracy and precision in rectal cancer treatment.

Cancer invasion to Auerbach's plexus is an important prognostic factor in patients with pT3-pT4 colorectal cancer

PURPOSE

By defining perineural invasion of colorectal cancer as invasion to Auerbach's plexus, we examined the usefulness of this pathologic finding as a prognostic factor.

METHODS

A total of 509 consecutive patients who underwent curative surgery for pT3 or pT4 colorectal cancer between May 1997 and December 2001 were reviewed. All the surviving patients were followed for more than five years. All the pathologic findings, including perineural invasion, were described prospectively in the pathology report forms.

RESULTS

Perineural invasion was detected in 132 of 509 patients (26 percent) and was significantly associated with lymph node status, lymphatic invasion, and venous invasion. Incidences of local and systemic recurrence were significantly higher in patients with perineural invasion than in those without perineural invasion. The disease-free survival of the perineural invasion-positive group was significantly poorer than that of the perineural invasion-negative group for Stages II and III colon cancer, irrespective of the use of adjuvant chemotherapy. This improved disease-free survival also was seen in patients with Stage II rectal cancer not treated with adjuvant chemotherapy. There was a nonsignificant difference in disease-free survival for Stage II rectal cancer and Stage III rectal cancer treated with chemotherapy, that of the perineural invasion-positive group being poorer. Multivariate analysis showed that lymph node status, perineural invasion, depth of invasion, and cancer site were significant prognostic factors.

CONCLUSIONS

Perineural invasion defined as cancer invasion to Auerbach's plexus is an important prognostic factor for colorectal cancer.

Efficacy of preoperative combined 18-fluorodeoxyglucose positron emission tomography and computed tomography for assessing primary rectal cancer response to neoadjuvant therapy

PURPOSE

Efficacy of F-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) for determining neoadjuvant therapy response in rectal cancer is not well established. We sought to evaluate serial FDG-PET/CT for assessing tumor down-staging, percentage residual tumor, and complete response or microscopic disease with rectal cancer neoadjuvant therapy.

METHODS

Patients with rectal cancer undergoing neoadjuvant therapy, definitive surgical resection, and FDG-PET/CT before and 4-6 weeks after neoadjuvant treatment were included. Tumors were evaluated pretreatment and on final pathology for size and stage. FDG-PET/CT parameters assessed were visual response score (VRS), standardized uptake value (SUV), PET-derived tumor volume (PETvol), CT-derived tumor volume (CTvol), and total lesion glycolysis (delta TLG).

RESULTS

Twenty-one rectal cancer patients over 3 years underwent neoadjuvant treatment, serial FDG-PET/CT, and resection. Complete response or microscopic disease (n = 7, 33%) was associated with higher Delta CTvol (AUC = 0.82, p = 0.004) and Delta SUV (AUC = 0.79, p = 0.01). Tumor down-staging (n = 14, 67%) was associated with greater Delta PETvol (AUC = 0.82, p < 0.001) and Delta SUV (AUC = 0.82, p < 0.001). Pathologic lymph node disease (n = 7, 33%) correlated with Delta CTvol (AUC = 0.75, p = 0.03) and Delta PETvol (AUC = 0.70, p = 0.08).

CONCLUSION

FDG-PET/CT parameters were best for assessing tumor down-staging and percentage of residual tumor after neoadjuvant treatment of rectal cancer and can potentially assist in treatment planning.

Prognostic factors after preoperative irradiation and surgery for locally advanced rectal cancer

AIMS

The experience of preoperative irradiation in clinically locally advanced rectal cancer for the period 1991-2003 is reported. Prognostic factors for survival and recurrence, and parameters for obtaining a free circumferential margin were evaluated.

METHODS

A prospective cohort study of 204 M0 patients given >45 Gy preoperatively (median age 66 years; 29% women; tumour level <16 cm from the anal verge).

RESULTS

Multivisceral and/or pelvic wall resections were performed in 61% of the patients. R0, R1 and R2 resections were achieved in 74%, 21% and 5%. Five-year survival was 52% for all patients, 60% for R0 resections, 31% for R1 and 0% for R2. The calculated 5-year recurrence rates were 13% for R0 resections and 24% for R1 resections (p<0.035). R-stage, N-stage, age, type of rectal resection and pelvic wall resection remained significant in Cox multivariate analysis for survival. Regarding local recurrence, the following parameters were independent: N-stage, carcinoembryonic antigen (CEA) response and pelvic wall resection. Medium high tumour level and reduced histopathological differentiation are important individual factors that seem to predict increased risk for not obtaining a R0 resection.

CONCLUSIONS

After preoperative irradiation and surgery, about 50% of the patients with locally advanced rectal cancer without overt metastases (M0) can be cured.

[Preoperative staging of rectal cancer]

Accurate preoperative staging of rectal cancer is crucial for therapeutic decision making, as local tumor extent, nodal status, and patterns of metastatic spread are directly associated with different treatment strategies. Recently, treatment approaches have been widely standardized according to large studies and consensus guidelines. Introduced by Heald, total mesorectal excision (TME) is widely accepted as the surgical procedure of choice to remove the rectum together with its enveloping tissues and the mesorectal fascia. Neoadjuvant radiochemotherapy also plays a key role in the treatment of locally advanced stages, while the use of new drugs will lead to a further improvement in oncological outcome. Visualization of the circumferential resection margin is the hallmark of any preoperative imaging and a prerequisite for high-quality TME surgery. The aim of this article is to present an overview on current cross-sectional imaging with emphasis on magnetic resonance imaging. Future perspectives in rectal cancer imaging are addressed.

Detection of recurrent rectal cancer with CT, MRI and PET/CT

Computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) all have the potential to directly visualize local and distant relapse of colorectal cancer (CRC). Nevertheless, the role of diagnostic imaging for routine follow-up of CRC patients remains controversial. Although MRI and PET have advantages over CT in the detection of local recurrence, until now only a few surveillance programs recommend the use of annual CT for routine follow-up. The objective of this review is to elucidate the current status of diagnostic imaging for the detection of recurrent rectal cancer based on the recent literature and our own experience. Furthermore, an insight into contemporary surveillance programs and an outlook concerning a novel technical approach to moving-table MRI at 1.5 Tesla for staging purposes are given.

Contemporary Imaging for Colorectal Cancer

With improvements in therapy for colorectal cancer, accurate imaging has taken on an increased significance. Preoperative diagnosis of metastatic disease helps identify patients who could undergo combined resection or might benefit from systemic therapy before surgery. Accurate imaging of rectal cancer is critical in evaluating locally advanced disease treatable by combined modality therapy, including chemoradiation and surgery. Postoperative imaging enhances identification of recurrent disease that might be amenable to salvage surgery.

Preoperative chemoradiation for rectal cancer: results of multimodality management and analysis of prognostic factors

BACKGROUND

Our goals were to examine the impact of neoadjuvant chemoradiation for rectal cancer on surgical outcomes and to determine prognostic factors predicting improved survival.

METHODS

Retrospective cohort of 56 male and 44 female patients.

RESULTS

After preoperative chemoradiation, 73% of patients had sphincter-preserving surgery. The 5-year disease-free (DFS) and overall survival rates were 77% and 81%, respectively. Twenty-five percent of patients showed a complete pathologic response. T-level downstaging and pathologic T stage did not correlate with recurrence or survival rates. Pathologic nodal stage was associated with a significant difference in recurrence rates (N(0) 19%, N1 20%, and N2 75%, P = .038) and DFS (N0/N1 vs. N2, 79% vs. 25%, P = .002).

CONCLUSION

Neoadjuvant chemoradiation resulted in a high rate of sphincter preservation. Complete pathologic responses after surgery were frequent and although pathologic T stage after surgery did not affect recurrence rates, pathologic nodal response was associated with improved recurrence and survival rates.

Combination of SELDI-TOF-MS and data mining provides early-stage response prediction for rectal tumors undergoing multimodal neoadjuvant therapy

OBJECTIVE

We investigated whether proteomic analysis of the low molecular weight region of the serum proteome could predict histologic response of locally advanced rectal cancer to neoadjuvant radiochemotherapy (RCT).

SUMMARY BACKGROUND DATA

Proteomic analysis of serum is emerging as a powerful new modality in cancer, in terms of both screening and monitoring response to treatment. No study has yet assessed its ability to predict and monitor the response of rectal cancer to RCT.

METHODS

Sequential serum samples from 20 patients undergoing RCT were prospectively collected. Time points sampled were as follows: pretreatment, 24/48 hours, 1 week, 2 weeks, 3 weeks, 5 weeks (last day of RCT), and presurgery. Response to treatment was measured using a 5-point tumor regression grade (TRG) based on the degree of residual tumor to fibrosis. All serum samples were analyzed in duplicate using surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS). Support vector machine (SVM) analysis of spectra was used to generate a predictive algorithm for each time point based on proteins that were maximally differentially expressed between good and poor responders. This algorithm was then tested using leave-one-out cross validation.

RESULTS

In total, 230 spectra were generated representing all available time points from 9 good responders (TRG 1+2) and 11 poor responders (TRG 3-5). SVM analysis indicated that changes within the serum proteome at the 24/48 hours time point into treatment provided optimal classification accuracy. In more detail, a cohort of 14 protein peaks were identified that collectively differentiated between good and poor responders, with 87.5% sensitivity and 80% specificity.

CONCLUSIONS

Serum proteomic analysis may represent an early response predictor in multimodal treatment regimens of rectal cancer. These data suggest that this novel, minimally invasive modality may be a useful adjunct in the multimodal management of rectal cancer, and in the design of future clinical trials.

A prospective pathologic analysis using whole-mount sections of rectal cancer following preoperative combined modality therapy: implications for sphincter preservation

OBJECTIVE

The aims of this study were to use a comprehensive whole-mount pathologic analysis to characterize microscopic patterns of residual disease, as well as circumferential and distal resection margins, in rectal cancer treated with preoperative CMT; and to identify clinicopathologic factors associated with residual disease.

SUMMARY BACKGROUND DATA

Recent studies have shown that preoperative combined modality therapy (CMT) for rectal cancer enhances rates of sphincter preservation. However, the efficacy of preoperative CMT in conjunction with a total mesorectal excision (TME)-based resection, in terms of resection margins using whole-mount sections, has not been reported. Furthermore, since patterns of residual disease and extent of distal spread following preoperative CMT are largely unknown, intraoperative determination of distal rectal transection remains a surgical challenge.

METHODS

We prospectively accrued 109 patients with endorectal ultrasound (ERUS)-staged, locally advanced rectal cancer (T2-T4 and/or N1), located a median distance of 7 cm from the anal verge, requiring preoperative CMT, and undergoing a TME-based resection. Comprehensive whole-mount pathologic analysis was performed, with particular emphasis on extent of residual disease, margin status, and intramural tumor extension. Clinicopathologic factors associated with residual disease were identified.

RESULTS

A sphincter-preserving resection was feasible in 87 patients (80%), and in all 109 patients, distal margins were negative (median, 2.1 cm; range, 0.4-10 cm). Intramural extension beyond the gross mucosal edge of residual tumor was observed in only 2 patients (1.8%), both < or =0.95 cm. There were no positive circumferential margins (median, 10 mm; range, 1-28 mm), although 6 were less than or equal to 1 mm. On multivariate analysis, residual disease was observed more frequently in distally located tumors (distance from anal verge <5 cm) (P = 0.03).

CONCLUSION

Our comprehensive pathologic analysis suggests that, following preoperative CMT and a TME-based resection, distal margins of 1 cm may provide for complete removal of locally advanced rectal cancer. Although residual cancer following preoperative CMT was more likely in the setting of distally located tumors, occult tumor beneath the mucosal edge was rare and, when present, limited to less than 1 cm. Our results extend the indications for sphincter preservation, as distal resection margins of only 1 cm may be acceptable for rectal cancer treated with preoperative CMT.

Usefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM: To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy.

METHODS: Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy (42 Gy during 18 d) and then to radical surgical treatment. The relationship between “T-downstaging” versus regressive changes expressed by tumor regression grade (TRG 1-5) and Nasierowska-Guttmejer classification (NG 1-3) was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN.

RESULTS: Complete regression (ypT0, TRG 1) was found in one patient. “T-downstaging” was observed in 11 (27.5%) patients. There was a weak statistical significance of the relationship between “T-downstaging” and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRG5. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG.

CONCLUSION: Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patients with rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between “T-downstaging” and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

Adjuvant chemoradiation for localized rectal cancer: current trends and future directions

Preoperative chemoradiation now represents the standard adjuvant care for patients with clinical stage II or III rectal cancer. The 5-year results of the German Chirurgische Arbeitsgemeinschaft Onkologie/Arbeitsgemeinschaft Radioonkologie/Arbeitsgemeinschaft Internistische Onkologie (CAO/ARO/AIO) 94 trial of preoperative vs. postoperative chemoradiation, using modern chemoradiation and total mesorectal surgical technique, clearly demonstrate marked improvements in treatment compliance, toxicity, tumor downstaging, sphincter-preservation rates for patients with low-lying tumors, and pelvic recurrence rates in favor of preoperative therapy. Moreover, recent randomized trials emphasize the importance of concurrent systemic therapy with this preoperative radiation strategy, as the addition of chemotherapy is associated with significant improvements in tumor downstaging, pathologic response, and local control over that achieved with radiation alone. Ongoing randomized phase II and III investigations incorporating novel systemic and biologic agents may refine our current preoperative chemoradiation and adjuvant therapy strategies. Such intensified treatment approaches will likely lead to future trials of risk-stratified management utilizing clinical, pathologic, and molecular factors, as well as to the further use of highly conformal radiation delivery techniques, such as intensity modulated radiation therapy.

Neoadjuvant radiochemotherapy for rectal cancer

During the past few decades, significant progress has been achieved in the management of rectal cancer with the introduction of total mesorectal excision. The role of radiotherapy in improving local control and survival has been investigated extensively. Randomized trials of preoperative radiotherapy reported statistically significant lower local recurrence rates with either short regimens (25 Gy in 5 fractions) or conventionally fractionated regimens (45-50 Gy in 25 fractions) and some also showed a survival improvement. Preoperative radiotherapy appears more effective in terms of local control and toxicity compared to postoperative therapy. Several recent studies show that 5-FU-based chemotherapy enhances tumor response to radiotherapy and preoperative chemoradiotherapy is being increasingly used for stage II and III disease.

Characteristics of recurrence and surveillance tools after curative resection for colorectal cancer: A multicenter study

BACKGROUND

The aim of this study was to clarify the characteristics of recurrence and the effectiveness of surveillance tools after curative resection for colorectal cancer.

METHODS

We enrolled 5230 consecutive patients (stage I, 1367; stage II, 1912; stage III, 1951) who underwent curative resection at 14 hospitals from 1991 to 1996. All patients were followed up intensively, and their outcomes were investigated retrospectively.

RESULTS

Of the 5230 patients, 906 developed recurrence. The recurrence rates of stage I, II, and III cancers were 3.7%, 13.3%, and 30.8%, respectively (P < .0001). The curves of the cumulative appearance rate of recurrence in stage II and III patients showed a rapid increase for the first 3 years. Recurrence after 5 years was less than 1% in each stage. Clinical visits combined with measurements of tumor markers detected the majority of recurrences except in the case of lung metastasis. In contrast, 43.4% of hepatic recurrences were detected by liver imaging, and 48.4% of pulmonary recurrences were noted by chest x-ray. The 5-year survival rates after primary colorectal surgery in patients who underwent resection for recurrence were better than in those without resection: 55% vs 11% in hepatic recurrence, 68% vs 13% in pulmonary recurrence, and 48% vs 22% in local recurrence (all P < .001).

CONCLUSION

It is useful to take these characteristics of recurrence into account in the management of patients after curative resection for colorectal cancer and in the setting of clinical trial for follow-up after curative resection for colorectal cancer.

Valor pronóstico de la afectación del margen circunferencial en pacientes con cáncer de recto localmente avanzado

INTRODUCTION

Circumferential resection margin (CRM) involvement in patients undergoing surgery for rectal tumors is a factor predicting poor prognosis in terms of the possibility of local recurrence, distant recurrence, and survival. CRM involvement has been related to the quality of the surgery. We analyzed the rate of CRM involvement in patients with locally-advanced rectal cancer undergoing neoadjuvant therapy and its relation with disease-free survival (DFS) and disease-specific survival (DSS).

MATERIAL AND METHODS

A total of 101 patients diagnosed with rectal adenocarcinoma between January 2001 and December 2001 who underwent surgery after receiving neoadjuvant radiochemotherapy were included. The CRM was considered positive when the distance between the tumor and the surgical border was less than 1 mm. The relation between CRM involvement and DFS and DSS was evaluated using the log-rank test.

RESULTS

The mean age was 66.6 years. The rate of CRM involvement was 10.8% (11 patients); CRM involvement was due to proximity or contact of the CRM with the tumor in 7 patients, proximity of enlarged nodes in 2 patients, perineural invasion in the CRM in 1 patient and discontinuous tumoral growth in 1 patient. With a mean follow-up of 25.4 months, disease recurrence was diagnosed in 13 patients: local recurrence occurred in 3 (2.97%) patients and distant metastases in 10 (9.9%). Eleven (10.8%) patients died from disease progression. CRM involvement was significantly related to DFS (p = 0.0167) and DSS (p = 0.0176).

CONCLUSION

In patients undergoing surgery for rectal cancer after neoadjuvant radiochemotherapy, CRM involvement is a negative prognostic factor for DFS and DSS.

Evaluation of safety of increased time interval between chemoradiation and resection for rectal cancer

BACKGROUND

Neoadjuvant chemoradiation is increasingly used for rectal cancer, with resection typically performed 6 weeks after completion of radiotherapy. We observed in our practice that further delay after radiotherapy led to increased downsizing. We performed this retrospective analysis to evaluate the safety of this approach.

METHODS

A retrospective review was performed of 48 patients with distal or mid-rectal cancer who were operated on 8 weeks or less after chemoradiation ended (group 1, n = 16), and more than 8 weeks later (group 2, n = 32). We looked at the effect of delaying surgery on intraoperative blood loss, operative and hospital duration, postoperative complications, readmissions, and mortality.

RESULTS

The median interval between radiation and operation was 7 weeks in group 1 and 11 weeks in group 2. There was no significant difference between the 2 groups in terms of intraoperative blood loss, postoperative complications, or readmissions. Length of operation and length of stay were slightly longer for group 2.

CONCLUSIONS

Delaying surgery after neoadjuvant treatment appears safe, with morbidity and mortality similar to that seen with surgery performed less than 8 weeks after chemoradiation.

Patterns of failure and survival for nonoperative treatment of stage c0 distal rectal cancer following neoadjuvant chemoradiation therapy

Neoadjuvant chemoradiation therapy (CRT) is the preferred treatment option for distal rectal cancer. Complete pathological response after CRT has led to the proposal of nonoperative approach as an alternative treatment for highly selected patients with complete clinical response. However, patterns of failure following this strategy remains undetermined. Three hundred sixty-one patients with distal rectal cancer were managed by neoadjuvant CRT including 5-FU, leucovorin, and 5040 cGy. Tumor response assessment was performed at 8 weeks following CRT. Patients with complete clinical response were not immediately operated on and were closely followed. One hundred twenty-two patients were considered to have complete clinical response after the first tumor response assessment. Of these, only 99 patients sustained complete clinical response for at least 12 months and were considered stage c0 (27.4%) and managed nonoperatively. Mean follow-up was 59.9 months. There were 13 (13.1%) recurrences: 5 (5%) endorectal, 7 (7.1%) systemic, and 1 (1%) combined recurrence. All 5 isolated endorectal recurrences were salvaged. Mean recurrence interval was 52 months for local failure and 29.5 months for systemic failure. There were five cancer-related deaths after systemic recurrences. Overall and disease-free 5-year survivals were 93% and 85%. Even though surgery remains the standard treatment for rectal cancer, nonoperative treatment after complete clinical response following neoadjuvant CRT may be safe and associated with good survival rates in a highly selected group of patients. Survival in these patients is significantly affected by systemic failure. Exclusive local failure occurs late after CRT completion and is frequently amenable to salvage therapy.

Patterns of failure and survival for nonoperative treatment of stage c0 distal rectal cancer following neoadjuvant chemoradiation therapy

Neoadjuvant chemoradiation therapy (CRT) is the preferred treatment option for distal rectal cancer. Complete pathological response after CRT has led to the proposal of nonoperative approach as an alternative treatment for highly selected patients with complete clinical response. However, patterns of failure following this strategy remains undetermined. Three hundred sixty-one patients with distal rectal cancer were managed by neoadjuvant CRT including 5-FU, leucovorin, and 5040 cGy. Tumor response assessment was performed at 8 weeks following CRT. Patients with complete clinical response were not immediately operated on and were closely followed. One hundred twenty-two patients were considered to have complete clinical response after the first tumor response assessment. Of these, only 99 patients sustained complete clinical response for at least 12 months and were considered stage c0 (27.4%) and managed nonoperatively. Mean follow-up was 59.9 months. There were 13 (13.1%) recurrences: 5 (5%) endorectal, 7 (7.1%) systemic, and 1 (1%) combined recurrence. All 5 isolated endorectal recurrences were salvaged. Mean recurrence interval was 52 months for local failure and 29.5 months for systemic failure. There were five cancer-related deaths after systemic recurrences. Overall and disease-free 5-year survivals were 93% and 85%. Even though surgery remains the standard treatment for rectal cancer, nonoperative treatment after complete clinical response following neoadjuvant CRT may be safe and associated with good survival rates in a highly selected group of patients. Survival in these patients is significantly affected by systemic failure. Exclusive local failure occurs late after CRT completion and is frequently amenable to salvage therapy.

[Curative vs palliative strategies in locoregional recurrence of gastrointestinal malignancies]

Locoregional recurrence is a relevant problem in surgical oncology. Intraluminal local relapse only occurs when the primary resection is carried through with inappropriate safety margins. If possible, a second surgical resection with wider margins is the treatment of choice. When the primary resection was appropriately done, extraluminal relapse in the original tumor bed indicates the primary tumor was already in an advanced stage. The indication for a second resection must be considered carefully. A realistic prospect of long-term tumor control exists only when the second resection yields tumor-free margins and is combined with chemo- and radiotherapy. There is usually no curative treatment option for recurrences in the draining lymph node region, the so-called fourth dimension.

Preoperative Radiotherapy Alone or Combined With Chemotherapy Followed by Transanal Excision for Rectal Adenocarcinoma

OBJECTIVE

To evaluate the efficacy of preoperative radiotherapy (RT) and chemoradiation (CRT) followed by transanal excision (TAE) for rectal adenocarcinoma.

METHODS

Thirty-two patients were treated between July 1988 and April 2004 and followed from 2 to 123 months (median, 27 months).

RESULTS

The 3-year outcomes were: locoregional control, 79%; distant metastasis-free survival, 80%; cause-specific survival, 88%; and overall survival, 75%. Outcomes were better for patients with T1-T2 tumors and those who experienced a complete response to preoperative RT or CRT. Two patients (6%) had chronic RT proctitis after treatment.

CONCLUSION

A select subset of patients with T2/T3 tumors will experience similar outcomes after preoperative RT or CRT and TAE compared with radical proctectomy. Reliably predictive clinicopathologic features to define this subgroup would best be elicited in the context of large prospective randomized trials, as would the optimal combination and schedule of systemic agents delivered in conjunction with preoperative RT. Patients who experience a complete response (cCR) after preoperative CRT are excellent candidates for TAE; those with less than a cCR have a less-favorable prognosis and are probably better treated with a low anterior resection or abdominal-perineal resection.

Assessment and management of the complete clinical response of rectal cancer to chemoradiotherapy

Preoperative chemoradiotherapy is considered by many as the preferred treatment strategy for distal rectal cancer. The observation of complete tumour regression has led to the proposition of nonoperative management of selected patients with complete clinical response (cCR) following treatment. We present results for the treatment of distal rectal cancer during 1991-2005. We have outlined the issues concerning adequate tumour assessment, the definition of complete response, and the advantages and disadvantages of conservative or surgical resection in patients with clinical and radiological evidence of cCR.

A pathologic complete response of rectal cancer to preoperative combined-modality therapy results in improved oncological outcome compared with those who achieve no downstaging on the basis of preoperative endorectal ultrasonography

BACKGROUND

Preoperative combined-modality therapy (CMT) is the preferred treatment for locally advanced rectal cancer (endorectal ultrasonography [ERUS] T3-4, N1, or clinically bulky) and achieves a pathologic complete response (pCR) in 4% to 33% of patients. However, the prognostic significance of pCR remains unclear.

METHODS

A prospectively collected database was queried to identify 200 patients with locally advanced disease treated from 1992 to 2002. The pCR group was defined as having no evidence of viable tumor on pathologic analysis. The no-downstaging group was defined as no difference between the pre-CMT ERUS stage and the pathologic stage. Those achieving some downstaging but not pCR were excluded. Patients were treated with CMT (5040 cGy of radiation and 5-fluorouracil-based chemotherapy) followed by surgery, and 51 (85%) in the pCR group and 129 (92%) in the no-downstaging group (P = .1) received postoperative chemotherapy. Recurrence-free survival (RFS) and overall survival (OS) were determined by using the Kaplan-Meier method.

RESULTS

The median follow-up was 38.6 months (range, 18.2-124.9 months). The pCR (n = 60) and control (n = 140) groups were similar in age (P = .6), sex (P = .4), distance of the tumor from the anal verge (P = .3), pre-CMT ERUS stage (P = .2), and comorbidities (P = .2). The 5-year RFS was 96% and 54% in the pCR and control groups, respectively (P < .00001); the 5-year OS was 90% and 68% (P = .009). Sphincter-preservation rates were higher in the pCR group (P = .01).

CONCLUSIONS

Rectal cancer patients with pCR after preoperative CMT have improved RFS, OS, and sphincter preservation compared with patients without downstaging. Because pCR seems to be associated with better outcome, an understanding of the factors governing the response to CMT should be pursued.

Modern management of rectal cancer: A 2006 update

The goal of this review is to outline some of the important surgical issues surrounding the management of patients with early (T1/T2 and N0), as well as locally advanced (T3/T4 and/or N1) rectal cancer. Surgery for rectal cancer continues to develop towards the ultimate goals of improved local control and overall survival, maintaining quality of life, and preserving sphincter, genitourinary, and sexual function. Information concerning the depth of tumor penetration through the rectal wall, lymph node involvement, and presence of distant metastatic disease is of crucial importance when planning a curative rectal cancer resection. Preoperative staging is used to determine the indication for neoadjuvant therapy as well as the indication for local excision versus radical cancer resection. Local excision is likely to be curative in most patients with a primary tumor which is limited to the submucosa (T1N0M0), without high-risk features and in the absence of metastatic disease. In appropriate patients, minimally invasive procedures, such as local excision, TEM, and laparoscopic resection allow for improved patient comfort, shorter hospital stays, and earlier return to preoperative activity level. Once the tumor invades the muscularis propria (T2), radical rectal resection in acceptable operative candidates is recommended. In patients with transmural and/or node positive disease (T3/T4 and/or N1) with no distant metastases, preoperative chemoradiation followed by radical resection according to the principles of TME has become widely accepted. During the planning and conduct of a radical operation for a locally advanced rectal cancer, a number of surgical management issues are considered, including: (1) total mesorectal excision (TME); (2) autonomic nerve preservation (ANP); (3) circumferential resection margin (CRM); (4) distal resection margin; (5) sphincter preservation and options for restoration of bowel continuity; (6) laparoscopic approaches; and (7) postoperative quality of life.

© 2006 The WJG Press. All rights reserved.

Neoadjuvant and adjuvant therapy for rectal cancer

The currently available evidence from randomized clinical trials clearly supports the use of adjuvant therapy in general and preoperative combined modality therapy in particular as effective means of decreasing the rates of local recurrence, improving sphincter preservation rates, and probably im-proving overall survival when managing patients with locally advanced adenocarcinomas of the lower two thirds of the rectum. A radical surgical approach with adequately performed, sharp TME remains the standard of care for those patients. There is clearly a need to develop and validate surrogate biomarkers for the identification of patients who respond favorably to preoperative treatment. There is still a significant fraction of rectal cancer patients who ultimately die from their disease. The armamentarium of avail-able therapies is evolving rapidly, and hopefully local control rates and overall survival of rectal cancer patients will continue to improve in the near future.

Neoadjuvant radiochemotherapy in the treatment of fixed and semi-fixed rectal tumors. Analysis of results and prognostic factors

PURPOSE

To report the retrospective analysis of patients with locally advanced rectal cancer treated with neodjuvant radiochemotherapy.

METHODS AND MATERIALS

From January 1994 to December 2003, 101 patients with fixed (25%) or semi-fixed (75%) rectal adenocarcinoma were treated by preoperative radiotherapy with a dose of 45 Gy at the whole pelvis and 50.4 Gy at primary tumor, concomitant to four weekly chemotherapies with 5-Fluorouracil (425 mg/m2) and Leucovorin (20 mg/m2). In 71 patients (70.3%) the primary tumor was located up to 6 cm from the anal verge and in 30 (29.7%) from 6.5 cm to 10 cm. Age, gender, tumor fixation, tumor distance from the anal verge, clinical response, surgical technique, and postoperative TNM stage were the prognostic factors analyzed for overall survival (OS), disease-free survival (DFS), and local control (LC) at five years.

RESULTS

Median follow-up time was 38 months (range, 2-141). Complete response was observed in eight patients (7.9%), partial in 54 (53.4%) and absence in 39 (38.7%). OS, DFS and LC were 52.6%, 53.8%, and 75.9%, respectively. Distant metastasis occurred in 40 (39.6%) patients, local recurrence in 20 (19.8%) and both in 16 (15.8%). Patients with fixed tumors had lower OS (17% Vs 65.6%; p < 0.001), DFS (31.2% Vs 60.9%; p = 0.005), and LC (58% Vs 82%; p = 0.004). Patients with tumors more than 6 cm above the anal verge had better LC (93% Vs 69%; p = 0.04). The postoperative TNM stage was a significant factor for DFS (I:64.1%, II:69.6%, III:35.2%, IV:11.1%; p < 0.001) and for LC (I:75.7%, II: 92.9%, III:54.1%, IV:100%; p = 0.005). Patients with positive lymph nodes had worse OS (37.9% Vs 70.4%, p = 0.006), DFS (32% Vs 72.7%, p < 0.001) and LC (56.2% Vs 93.4%; p < 0.001).

CONCLUSION

This study suggests that the neoadjuvant treatment employed was effective for local control. Fixation of the lesion and lymph nodes metastasis were the main adverse prognostic factors. Distant failures were frequent, supporting the need of new drugs for adjuvant chemotherapy.

Prognostic factors for disease-free survival in patients with T3–4 or N+ rectal cancer treated with preoperative chemoradiation therapy, surgery, and intraoperative irradiation

PURPOSE

Fluoropyrimidine-radiosensitizing agents in conjunction with preoperative radiotherapy have proven to induce tumor and nodal downstaging effects, sphincter preservation promotion, and mid-term favorable survival rates. Intraoperative electron beam radiation therapy may improve pelvic control in patients with locally advanced rectal cancer stages. Potential predictive factors for response and disease-free survival, with intense local multidisciplinary approach, are analyzed.

METHODS AND MATERIALS

One hundred fifteen patients with rectal cancer were treated with oral 5-fluorouracil or Tegafur with preoperative radiotherapy, surgery, and intraoperative electron beam radiation therapy to identify potential pre- and on-treatment characteristics that might be of prognostic value for disease outcome. Univariate and multivariate analyses were performed.

RESULTS

Older patients and those treated with Tegafur were more likely to achieve a major histologic response, categorized as persistence of minimal residual microscopic disease foci in the surgical specimen ("mic" response). Factors unfavorably associated with disease-free survival in the multivariate model were male gender and persistence of macroscopic disease in the rectal wall ("mac" response). Accordingly, 3-year disease-free survival rates in the groups of patients with 0, 1, or 2 of these risk factors were 100%, 81%, and 53%, respectively (p < 0.001).

CONCLUSIONS

Females with an intense pathologic response (pT(mic) residue) to preoperative chemoradiotherapy have an excellent 3-year disease-free survival. This information might be of interest for stratification of patients in the development of adjuvant treatment trials.

Colorectal cancer surveillance: 2005 update of an American Society of Clinical Oncology practice guideline

PURPOSE

To update the 2000 American Society of Clinical Oncology guideline on colorectal cancer surveillance.

RECOMMENDATIONS

Based on results from three independently reported meta-analyses of randomized controlled trials that compared low-intensity and high-intensity programs of colorectal cancer surveillance, and on recent analyses of data from major clinical trials in colon and rectal cancer, the Panel recommends annual computed tomography (CT) of the chest and abdomen for 3 years after primary therapy for patients who are at higher risk of recurrence and who could be candidates for curative-intent surgery; pelvic CT scan for rectal cancer surveillance, especially for patients with several poor prognostic factors, including those who have not been treated with radiation; colonoscopy at 3 years after operative treatment, and, if results are normal, every 5 years thereafter; flexible proctosigmoidoscopy [corrected] every 6 months for 5 years for rectal cancer patients who have not been treated with pelvic radiation; history and physical examination every 3 to 6 months for the first 3 years, every 6 months during years 4 and 5, and subsequently at the discretion of the physician; and carcinoembryonic antigen every 3 months postoperatively for at least 3 years after diagnosis, if the patient is a candidate for surgery or systemic therapy. Chest x-rays, CBCs, and liver function tests are not recommended, and molecular or cellular markers should not influence the surveillance strategy based on available evidence.