Ten-year results of preoperative radiation followed by sphincter preservation for rectal cancer: increased local failure rate in nonresponders

Study of therapeutic results, lymph node ratio, short-term and long-term complications of lateral lymph node dissection in rectal cancer patients

Objectives

This study aimed to assess disease free survival, lymph node ratio (LNR) and complication rate among advanced mid to low rectal cancer patients (stage 2-3) who underwent total mesorectal excision (TME) and lateral lymph node dissection (LLND) at the Iran Cancer Institute in 2016-2018.

Material and Methods

The study was carried out on 32 patients treated by curative surgery and lateral lymph node dissection at the Iran Cancer Institute from 2016 March to 2018 March. Chi-square test was used to assess the distribution of dichotomous clinical outcomes by sex. We also used Breslow test in Kaplan-Meier approach to estimate 1-year disease free survival and corresponding 95% confidence intervals (CI).

Results

Of the 279 dissected lymph nodes by TME, 42 nodes (in mesorectal) and of the 232 dissected lymph nodes by LLND, 7 nodes (in iliac, para-iliac and obturator) were positive for metastasis. Higher local recurrence was observed in men (three patients) compared to women (one patient) which was not statistically significant (p= 0.878). We also observed higher 1-year disease free survival rate in women (1-year disease free survival= 93.3%) compared to men (1-year disease free survival= 82.4%), which also was not statistically significant (p= 0.356). 1-year disease free survival rate in patient with negative lymph nodes was 95.5% while respective number in patients with positive lymph nodes was 70% (p= 0.047).

Conclusion

TME with LLND could prolong survival and reduce local recurrence in patients with advanced low rectal cancer. However, large-scale clinical trials are required to evaluate such procedure as a standard in Iran.

Surgical strategy for low rectal cancers

The two goals of surgery for lower rectal cancer surgery are to obtain clear "curative" margins and to limit post-surgical functional disorders. The question of whether or not to preserve the anal sphincter lies at the center of the therapeutic choice. Histologically, tumor-free distal and circumferential margins of>1mm allow a favorable oncologic outcome. Whether such margins can be obtained depends of TNM staging, tumor location, response to chemoradiotherapy and type of surgical procedure. The technique of intersphincteric resection relies on these narrow margins to spare the sphincter. This procedure provides satisfactory oncologic outcome with a rate of circumferential margin involvement ranging from 5% to 11%, while good continence is maintained in half of the patients. The extralevator abdominoperineal resection provides good oncologic results, however this procedure requires a permanent colostomy. A permanent colostomy alters several domains of quality of life when located at the classical abdominal site but not when brought out at the perineal site as a perineal colostomy.

New application of dual point 18F-FDG PET/CT in the evaluation of neoadjuvant chemoradiation response of locally advanced rectal cancer

PURPOSE

FDG PET/CT has been suggested as the most reliable modality to predict pathological tumor responses after neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC). However, several confounding factors including radiation-induced inflammation could not be easily avoided with the commonly used single-point FDG PET/CT. Our aim was to evaluate the accuracy of a dual-point PET/CT protocol in LARC response prediction to CRT.

PATIENTS AND METHODS

Sixty-one LARC patients were enrolled and treated with neoadjuvant CRT. PET/CT was performed before and after CRT. Dual-point acquisition was applied to post-CRT PET/CT. Post-CRT SUVmax (postSUV), pre/post-CRT SUVmax change (RI), and dual-point index (DI) of post-CRT PET/CT were compared with the Dworak tumor regression grade (TRG) as a gold standard. Univariate and multivariate analyses, as well as receiver operating characteristic curve analysis, were used to evaluate the predictive ability of demographic, clinical, and metabolic PET parameters.

RESULTS

Fifteen patients of TRG3-4 were defined as pathological responders, and 46 patients of TRG1-2 were nonresponders. The resulting response index (RI) ranged from -13 to 94.8% (59.1±22.0%), and delay index (DI) ranged from -45.2 to 25.0% (-9.1±12.1%). Univariate analysis resulted in PET parameters (postSUV, RI, and DI) as significant predictors (P=0.004, P<0.001, P<0.0001). According to multivariate analysis, RI and DI remained as significant predictors (P=0.04 and P=0.0004). Receiver operating characteristic analysis showed that DI had significantly higher area under the curve compared with RI (0.906 vs 0.696, P=0.018). Delay index had 86.7% sensitivity, 87.0% specificity, 68.4% positive predictive value, 95.2% negative predictive value, and 86.9% accuracy.

CONCLUSIONS

Dual-point post-CRT PET/CT can predict pathological tumor response better than conventional single time point pre- and post-CRT PET/CT.

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.

Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis

BACKGROUND

Complete pathologic response (CPR) after neoadjuvant chemoradiotherapy (combined modality treatment, CMT) for rectal cancer seems associated with improved survival compared to partial or no response (NPR). However, previous reports have been limited by small sample size and single-institution design.

METHODS

A systematic literature review was conducted to detect studies comparing long-term results of patients with CPR and NPR after CMT for rectal cancer. Variables were pooled only if evaluated by 3 or more studies. Study end points included rates of CPR, local recurrence (LR), distant recurrence (DR), 5-year overall survival (OS), and disease-free survival (DFS).

RESULTS

Twelve studies (1,913 patients) with rectal cancer treated with CMT were included. CPR was observed in 300 patients (15.6%). CPR and NPR patient groups were similar with respect to age, sex, tumor size, distance of tumor from the anus, and stage of disease before treatment. Median follow-up ranged from 23 to 46 months. CPR patients had lower rates of LR [0.7% vs. 2.6%; odds ratio (OR) 0.45, 95% confidence interval (CI) 0.22-0.90, P = 0.03], DR (5.3% vs. 24.1%; OR 0.15, 95% CI 0.07-0.31, P = 0.0001), and simultaneous LR + DR (0.7% vs. 4.8%; OR 0.32, 95% CI 0.13-0.79, P = 0.01). OS was 92.9% for CPR versus 73.4% for NPR (OR 3.6, 95% CI 1.84-7.22, P = 0.002), and DFS was 86.9% versus 63.9% (OR 3.53, 95% CI 1.62-7.72, P = 0.002).

CONCLUSIONS

CPR after CMT for rectal cancer is associated with improved local and distal control as well as better OS and DFS.

Risk factors for local recurrence of middle and lower rectal carcinoma after curative resection

AIM: To explore the risk factors for local recurrence of middle and lower rectal carcinoma after curative resection.

METHODS: Specimens of middle and lower rectal carcinoma from 56 patients who received curative resection at the Department of General Surgery of Guangdong Provincial People’s Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. The relations between clinicopathologic characteristics, mesorectal metastasis and circumferential resection margin status were identified in patients with local recurrence of middle and lower rectal carcinoma.

RESULTS: Local recurrence of middle and lower rectal carcinoma after curative resection occurred in 7 of the 56 patients (12.5%), and was significantly associated with family history (χ² = 3.929, P = 0.047), high CEA level (χ² = 4.964, P = 0.026), cancerous perforation (χ² = 8.503, P = 0.004), tumor differentiation (χ² = 9.315, P = 0.009) and vessel cancerous emboli (χ² = 11.879, P = 0.001). In contrast, no significant correlation was found between local recurrence of rectal carcinoma and other variables such as age (χ² = 0.506, P = 0.477), gender (χ² = 0.102, χ² = 0.749), tumor diameter (χ² = 0.421, P = 0.516), tumor infiltration (χ² = 5.052, P = 0.168), depth of tumor invasion (χ² = 4.588, P = 0.101), lymph node metastases (χ² = 3.688, P = 0.055) and TNM staging system (χ² = 3.765, P = 0.152). The local recurrence rate of middle and lower rectal carcinoma was 33.3% (4/12) in patients with positive circumferential resection margin and 6.8% (3/44) in those with negative circumferential resection margin. There was a significant difference between the two groups (χ² = 6.061, P = 0.014). Local recurrence of rectal carcinoma occurred in 6 of 36 patients (16.7%) with mesorectal metastasis, and in 1 of 20 patients (5.0%) without mesorectal metastasis. However, there was no significant difference between the two groups (χ² = 1.600, P = 0.206).

CONCLUSION: Family history, high CEA level, cancerous perforation, tumor differentiation, vessel cancerous emboli and circumferential resection margin status are the significant risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. Local recurrence may be more frequent in patients with mesorectal metastasis than in patients without mesorectal metastasis.

Locally advanced rectal cancer: what is the evidence for induction chemoradiation?

The concept of spatial cooperation in neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer is attractive. Chemotherapy may, as a component of CRT, not only act as a radiosensitizing agent but also potentially eradicate distant micrometastases. Recent trials have demonstrated that the addition of concurrent 5-fluorouracil (5-FU)-based chemotherapy to radiation increases the pathological complete response rate, and reduces local recurrence, but as yet, a survival advantage has not been observed.

AIMS

This review aims to examine the evidence for induction CRT in locally advanced rectal cancer. The endpoints of pathological complete response, a negative circumferential margin, sphincter-sparing surgery, local control, disease-free survival (DFS), and overall survival (OS) are examined, as are acute and late morbidity, surgical complications, and late functional results.

METHODS

The information to produce this review was compiled by searching PubMed and MEDLINE for English language articles published until April 2007. The search term included "induction, neoadjuvant, chemotherapy, radiotherapy, chemoradiation, combined modality" in association with rectal cancer.

CONCLUSIONS

CRT in the European randomized trials of rectal cancer improves tumor downstaging, pathological complete response, and local control over radiotherapy alone, but does not translate into a benefit in terms of longer DFS or OS, or a higher chance of sphincter preservation. Metastatic disease remains a significant problem, which provides a strong rationale for the integration of a second cytotoxic drug, or biologically targeted agents.

Prognostic value of lateral lymph node metastasis for advanced low rectal cancer

AIM

To evaluate the risk factors for lateral lymph node metastasis in patients with advanced low rectal cancer, in order to make the effective selection of patients who could benefit from lateral lymph node dissection, as well as the relationship of lateral lymph node metastasis with local recurrence and survival of patients with advanced low rectal cancer.

METHODS

A total of 96 consecutive patients who underwent curative surgery with lateral pelvic lymphadenectomy for advanced lower rectal cancer were retrospectively analyzed. The relation of lateral lymph node metastasis with clinicopathologic characteristics, local recurrence and survival of patients was identified.

RESULTS

Lateral lymph node metastasis was observed in 14.6% (14/96) of patients with advanced low rectal cancer. Lateral lymph node metastasis was detected in 10 (25.0%) of 40 patients with tumor diameter >or= 5 cm and in 4 (7.1%) of 56 patients with tumor diameter < 5 cm. The difference between the two groups was statistically significant (c2 = 5.973, P = 0.015). Lateral lymph node metastasis was more frequent in patients with 4/4 diameter of tumor infiltration (7 of 10 cases, 70.0%), compared with patients with 3/4, 2/4 and 1/4 diameter of tumor infiltration (3 of 25 cases, 12.0%; 3 of 45 cases, 6.7%; 1 of 16 cases, 6.3%) (c2 = 27.944, P = 0.0001). The lateral lymph node metastasis rate was 30.0% (9 of 30 cases), 9.1% (4 of 44 cases) and 4.5% (1 of 22 cases) for poorly, moderately and well-differentiated carcinoma, respectively. The difference between the three groups was statistically significant (c2 = 8.569, P = 0.014). Local recurrence was 18.8% (18 of 96 cases), 64.3% (9 of 14 cases), and 11.0% (9 of 82 cases) in patients with advanced low rectal cancer, in those with and without lateral lymph node metastasis, respectively. The difference between the two groups was statistically significant (c2 = 22.308, P = 0.0001). Kaplan-Meier survival analysis showed significant improvements in median survival (80.9 +/- 2.1 m, 95% CI: 76.7-85.1 m vs 38 +/- 6.7 m, 95% CI: 24.8-51.2 m) of patients without lateral lymph node metastasis compared with those with lateral lymph node metastasis (log-rank, P = 0.0001).

CONCLUSION

Tumor diameter, infiltration and differentiation are significant risk factors for lateral lymph node metastasis. Lateral pelvic lymphadenectomy should be performed following surgery for patients with tumor diameter >or= 5 cm. Lateral lymph node metastasis is an important predictor for local recurrence and survival in patients with advanced low rectal cancer.

Long-term efficacy of preoperative radiotherapy for locally advanced low rectal cancer

BACKGROUND AND AIMS

The purpose of this study was to assess the long-term efficacy of preoperative radiotherapy for locally advanced low rectal cancer.

MATERIALS AND METHODS

Between April 1990 and June 2005, all patients who underwent surgery for low rectal cancer with a pretreatment diagnosis of T3 or resectable T4 without distant metastasis were enrolled. The total dose of radiation was 45 Gy. Patients with a partial or complete response were defined as radiotherapy responders (RT-R) and the others as radiotherapy non-responders (RT-NR). Patients who did not receive radiotherapy were termed the non-radiotherapy group (NRT). The endpoint of this study was overall survival and local and/or distant metastasis.

RESULTS

There were 24 patients in RT-R, 26 in RT-NR, and 40 in NRT. Gastrointestinal complications were commonly observed in all groups. RT-R had a significantly higher incidence of genitourinary complications. Five-year overall survival rate was 79.6% in RT-R, 58.9% in RT-NR, and 58.8% in NRT. The difference was significant in favor of RT-R over the others (P=0.015, 0.024, respectively). Five-year local recurrence-free survival rate was 100% in RT-R, 81.5% in RT-NR, and 74.9% in NRT. RT-R had significantly improved local control compared with the others (P=0.034, 0.021, respectively). Five-year distant metastasis-free survival was not statistically different among all groups.

CONCLUSIONS

Survival benefit of preoperative radiotherapy was limited to responders. Considering the increased risk of adverse effects, identification of predictors of radiosensitivity is required in order to provide the most suitable treatment for individual patients.

Prognostic value of lateral lymph node metastasis for advanced low rectal cancer

AIM: To evaluate the risk factors for lateral lymph node metastasis in patients with advanced low rectal cancer, in order to make the effective selection of patients who could benefit from lateral lymph node dissection, as well as the relationship of lateral lymph node metastasis with local recurrence and survival of patients with advanced low rectal cancer.

METHODS: A total of 96 consecutive patients who underwent curative surgery with lateral pelvic lymphadenectomy for advanced lower rectal cancer were retrospectively analyzed. The relation of lateral lymph node metastasis with clinicopathologic characteristics, local recurrence and survival of patients was identified.

RESULTS: Lateral lymph node metastasis was observed in 14.6% (14/96) of patients with advanced low rectal cancer. Lateral lymph node metastasis was detected in 10 (25.0%) of 40 patients with tumor diameter ≥ 5 cm and in 4 (7.1%) of 56 patients with tumor diameter < 5 cm. The difference between the two groups was statistically significant (χ² = 5.973, P = 0.015). Lateral lymph node metastasis was more frequent in patients with 4/4 diameter of tumor infiltration (7 of 10 cases, 70.0%), compared with patients with 3/4, 2/4 and 1/4 diameter of tumor infiltration (3 of 25 cases, 12.0%; 3 of 45 cases, 6.7%; 1 of 16 cases, 6.3%) (χ² = 27.944, P = 0.0001). The lateral lymph node metastasis rate was 30.0% (9 of 30 cases), 9.1% (4 of 44 cases) and 4.5% (1 of 22 cases) for poorly, moderately and well-differentiated carcinoma, respectively. The difference between the three groups was statistically significant (χ² = 8.569, P = 0.014). Local recurrence was 18.8% (18 of 96 cases), 64.3% (9 of 14 cases), and 11.0% (9 of 82 cases) in patients with advanced low rectal cancer, in those with and without lateral lymph node metastasis, respectively. The difference between the two groups was statistically significant (χ² = 22.308, P = 0.0001). Kaplan-Meier survival analysis showed significant improvements in median survival (80.9 ± 2.1 m, 95% CI: 76.7-85.1 m vs 38 ± 6.7 m, 95% CI: 24.8-51.2 m) of patients without lateral lymph node metastasis compared with those with lateral lymph node metastasis (log-rank, P = 0.0001).

CONCLUSION: Tumor diameter, infiltration and differentiation are significant risk factors for lateral lymph node metastasis. Lateral pelvic lymphadenectomy should be performed following surgery for patients with tumor diameter ≥ 5 cm. Lateral lymph node metastasis is an important predictor for local recurrence and survival in patients with advanced low rectal cancer.

Limitations of early rectal cancer nodal staging may explain failure after local excision

Successful selection of patients with rectal cancer for local excision requires accurate preoperative lymph node staging. Although endorectal ultrasound is capable of detecting locally advanced disease, its ability to correctly identify nodal metastases in early rectal lesions is less well described. This study examines the accuracy of endorectal ultrasound in determining nodal stage based on depth of penetration of the primary lesion (T stage). Between 1998 and 2003, endorectal ultrasound was performed on 938 consecutive patients; 134 had biopsy-proven rectal cancers and were treated with radical resection, without neoadjuvant therapy. Lymph node metastases were measured pathologically and correlated with endorectal ultrasound and clinicopathologic features. Accuracy and specificity of endorectal ultrasound nodal staging was determined. The overall accuracy of endorectal ultrasound nodal staging for the study cohort was 70 percent, with a 16 percent false-positive rate and 14 percent false-negative rate. Endorectal ultrasound was more likely to overlook small metastatic lymph node deposits. The size of lymph node metastasis and accuracy of endorectal ultrasound nodal staging was related to T stage. The specificity of endorectal ultrasound nodal staging, or the ability to identify patients who were node-negative, was dependent on T stage. Early rectal lesions are more likely to have lymph node micrometastases not detected by endorectal ultrasound. The ability of endorectal ultrasound to correctly identify patients without lymph node metastasis is dependent on the T stage of the primary lesion. The limitations of endorectal ultrasound in accurately staging nodal disease in early rectal lesions may, in part, explain the relatively high recurrence rates seen after local excision.

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.

Impact des traitements préopératoires (radiothérapie et chimiothérapie) dans la conservation sphinctérienne des cancers du très bas rectum

Sphincter preservation for low rectal carcinoma must be evaluated with a plurifactoriel approach. Multicentric randomised studies are unable to demonstrate a relationship between complete tumoral response and conservative sphincteric rate. Intersphincteric resection technique is becoming a main factor to transform conservative indication. Complete tumoral response should not be the only purpose of future trials.