Revised tumor and node categorization for rectal cancer based on surveillance, epidemiology, and end results and rectal pooled analysis outcomes

Magnetic resonance imaging-detected tumor response for locally advanced rectal cancer predicts survival outcomes: MERCURY experience

PURPOSE

To assess magnetic resonance imaging (MRI) and pathologic staging after neoadjuvant therapy for rectal cancer in a prospectively enrolled, multicenter study.

METHODS

In a prospective cohort study, 111 patients who had rectal cancer treated by neoadjuvant therapy were assessed for response by MRI and pathology staging by T, N and circumferential resection margin (CRM) status. Tumor regression grade (TRG) was also assessed by MRI. Overall survival (OS) was estimated by using the Kaplan-Meier product-limit method, and Cox proportional hazards models were used to determine associations between staging of good and poor responders on MRI or pathology and survival outcomes after controlling for patient characteristics.

RESULTS

On multivariate analysis, the MRI-assessed TRG (mrTRG) hazard ratios (HRs) were independently significant for survival (HR, 4.40; 95% CI, 1.65 to 11.7) and disease-free survival (DFS; HR, 3.28; 95% CI, 1.22 to 8.80). Five-year survival for poor mrTRG was 27% versus 72% (P = .001), and DFS for poor mrTRG was 31% versus 64% (P = .007). Preoperative MRI-predicted CRM independently predicted local recurrence (LR; HR, 4.25; 95% CI, 1.45 to 12.51). Five-year survival for poor post-treatment pathologic T stage (ypT) was 39% versus 76% (P = .001); DFS for the same was 38% versus 84% (P = .001); and LR for the same was 27% versus 6% (P = .018). The 5-year survival for involved pCRM was 30% versus 59% (P = .001); DFS, 28 versus 62% (P = .02); and LR, 56% versus 10% (P = .001). Pathology node status did not predict outcomes.

CONCLUSION

MRI assessment of TRG and CRM are imaging markers that predict survival outcomes for good and poor responders and provide an opportunity for the multidisciplinary team to offer additional treatment options before planning definitive surgery. Postoperative histopathology assessment of ypT and CRM but not post-treatment N status were important postsurgical predictors of outcome.

Lymph nodes, tumor deposits, and TNM: are we getting better?

PURPOSE

New editions of the TNM staging system for colorectal cancer have been subject to extensive criticism. In the current study, we evaluate each edition of TNM and analyze stage migration caused by the different versions.

PATIENTS AND METHODS

Two independent test populations were used: participants derived from a randomized surgical trial from the United Kingdom (n = 455) and patients from a population-based series from Sweden (n = 505). All slides from these patient cases were reviewed with special attention for the presence of tumor deposits. Tumor deposits were classified according to the fifth, sixth, and seventh editions of TNM and correlated with prognosis.

RESULTS

Every change in edition of TNM led to a stage migration of between 33% and 64% in patients with tumor deposits. Reproducibility was best in the fifth edition of TNM. The prognostic value of the seventh edition was best only when all tumor deposits irrespective of size or contour were included as lymph nodes. The prognostic value of the fifth edition was better than that of the sixth.

CONCLUSION

We demonstrate there is a place for tumor deposits in the staging of patients with colorectal cancer. However, many questions remain about their definition and the reproducibility and use of this category in special situations, such as after neoadjuvant treatment. These should be the subject of additional research before use as a factor in TNM staging. This work demonstrates the necessity of testing modifications before their introduction.

Transanal endoscopic microsurgery for residual rectal cancer after neoadjuvant chemoradiation therapy is associated with significant immediate pain and hospital readmission rates

BACKGROUND

Transanal endoscopic microsurgery may represent appropriate diagnostic and therapeutic procedure in selected patients with distal rectal cancer following neoadjuvant chemoradiation. Even though this procedure has been associated with low rates of postoperative complications, patients undergoing neoadjuvant chemoradiation seem to be at increased risk for suture line dehiscence. In this setting, we compared the clinical outcomes of patients undergoing transanal endoscopic microsurgery with and without neoadjuvant chemoradiation.

METHODS

Thirty-six consecutive patients were treated by transanal endoscopic microsurgery at a single institution. Twenty-three patients underwent local excision after neoadjuvant chemoradiation therapy for rectal adenocarcinoma, and 13 patients underwent local excision without any neoadjuvant treatment for benign and malignant rectal tumors. Chemoradiation therapy included 50.4 to 54 Gy and 5-fluorouracil-based chemotherapy. All patients underwent transanal endoscopic microsurgery with primary closure of the rectal defect. Complications (immediate and late) and readmission rates were compared between groups.

RESULTS

Overall, median hospital stay was 2 days. Immediate (30-d) complication rate was 44% for grade II/III complications. Patients undergoing neoadjuvant chemoradiation therapy were more likely to develop grade II/III immediate complications (56% vs 23%; P = .05). Overall, the 30-day readmission rate was 30%. Wound dehiscence was significantly more frequent among patients undergoing neoadjuvant chemoradiation therapy (70% vs 23%; P = .03). Patients undergoing neoadjuvant chemoradiation therapy were at significantly higher risk of requiring readmission (43% vs 7%; P = .02).

CONCLUSION

Transanal local excision with the use of endoscopic microsurgical approach may result in significant postoperative morbidity, wound dehiscence, and readmission rates, in particular, because of rectal pain secondary to wound dehiscence. In this setting, the benefits of this minimally invasive approach either for diagnostic or therapeutic purposes become significantly restricted to highly selected patients that can potentially avoid a major operation but will still face a significantly morbid and painful procedure.

Does stage II colorectal cancer need to be redefined?

Detection of guanylyl cyclase C mRNA in lymph nodes of resected stage II colorectal cancer is highly correlated with the risk of tumor recurrence. If validated, these results could have significant implications for the selection of patients for adjuvant therapy in this disease.

Interleukin-24 is correlated with differentiation and lymph node numbers in rectal cancer

AIM: To assess the significance of interleukin (IL)-24 and vascular endothelial growth factor (VEGF) expression in lymph-node-positive rectal cancer.

METHODS: Between 1998 and 2005, 90 rectal adenocarcinoma patients with lymph node involvement were enrolled. All patients received radical surgery and postoperative pelvic chemoradiotherapy of 50.4-54.0 Gy. Chemotherapy of 5-fluorouracil and leucovorin or levamisole was given intravenously during the first and last week of radiotherapy, and then monthly for about 6 mo. Expression of IL-24 and VEGF was evaluated by immunohistochemical staining of surgical specimens, and their relations with patient characteristics and survival were analyzed. The median follow-up of surviving patients was 73 mo (range: 52-122 mo).

RESULTS: IL-24 expression was found in 81 out of 90 patients; 31 showed weak intensity and 50 showed strong intensity. VEGF expression was found in 64 out of 90 patients. Negative and weak intensities of IL-24 expression were classified as negative expression for analysis. IL-24 expression was significantly reduced in poorly differentiated tumors in comparison with well or moderately differentiated tumors (P = 0.004), N2b to earlier N stages (P = 0.016), and stage IIIc to stage IIIa or IIIb (P = 0.028). The number of involved lymph nodes was also significantly reduced in IL-24-positive patients in comparison with IL-24-negative ones.There was no correlation between VEGF expression and patient characteristics. Expression of IL-24 and VEGF was not correlated with survival, but N stage and stages were significantly correlated with survival.

CONCLUSION: IL-24 expression was significantly correlated with histological differentiation, and inversely correlated with the degree of lymph node involvement in stage III rectal cancer.

Colorectal tumors: the histology report

Epithelial colorectal tumors are common pathologic entities. Their histology report should be comprehensive of a series of pathologic parameters essential for the correct clinical management of the patients. Diagnostic histologic criteria of adenomatous, serrated, inflammatory, and hamartomatous polyps and of polyposis syndromes are discussed. In addition, the pathologic features of early and advanced colorectal cancer are described and a checklist is given. Finally, molecular prognostic and predictive factors currently employed in the treatment of colorectal cancer are discussed.

Molecular profiling of colon tumors: the search for clinically relevant biomarkers of progression, prognosis, therapeutics, and predisposition

If properly translated to clinical use, our knowledge about biomarkers may lead to a more effective way of combating colorectal cancer (CRC). Biomarkers are biomolecular, genetic, or cytogenetic attributes indicative of the disease's progression, predisposition, prognosis, or therapeutic options. For CRC, these include chromosomal instability, mutations in KRAS and TP53, loss of 18q, and elevated level of carcinoembryonic antigen (CEA), which are all associated with poor prognosis. The prognostic significance of 18q loss can be attributed to reduced expression of SMAD4, or DCC, although the chromosomal arm is actually heavily populated by genes whose downregulation correlate to worse survival. Potentially, identification of prognostic biomarkers can help the oncologist decide whether adjuvant chemotherapy is necessary after surgery. Testing for therapeutic biomarkers can be necessary if targeted therapeutics are being considered. The identification of highly penetrant predisposition markers (such as mutations in APC and MLH1) can be a lifesaver for carrier individuals, who would then have to undergo colonoscopy at an earlier age. Even sporadic CRCs may have some hereditary components, according to recent studies. Genome-wide association studies (using SNP arrays) showed that polymorphisms of certain genes can have subtle influence on CRC predisposition. Our own SNP array-based analysis suggested that long stretches of germline homozygosity (autozygosity), indicative of consanguinity, may also factor in CRC predisposition.

The clinical significance of circulating tumor cells in non-metastatic colorectal cancer--a review

BACKGROUND

Finding a clinical tool to improve the risk stratification and identifying those colorectal cancer patients with an increased risk of recurrence is of great importance. The presence of circulating tumor cells (CTC) in peripheral blood can be a strong marker of poor prognosis in patients with metastatic disease, but the prognostic role of CTC in non-metastatic colorectal cancer is less clear. The aim of this review is to examine the possible clinical significance of circulating tumor cells in non-metastatic colorectal cancer (TNM-stage I-III) with the primary focus on detection methods and prognosis.

METHODS

The PubMed and Cochrane database and reference lists of relevant articles were searched for scientific literature published in English from January 2000 to June 2010. We included studies with non-metastatic colorectal cancer (TNM-stage I-III) and CTC detected pre- and/or post-operatively in peripheral blood.

RESULTS

Nine studies qualified for further analyses. Detection rates of CTC in peripheral blood of patients with non-metastatic colorectal cancer varied from 4% to 57%. Seven studies applied RT-PCR and two studies used immunocytochemical methods. Seven studies found the presence of CTC to be a prognostic marker of poor disease-free survival.

CONCLUSION

The presence of CTC in peripheral blood is a potential marker of poor disease-free survival in patients with non-metastatic colorectal cancer. The low abundance of CTC in non-metastatic colorectal cancer requires very sensitive and specific detection methods. An international consensus on choice of detection method and markers, is warranted before incorporating CTC into risk stratification in the clinical setting.

Assessment of Serosal Invasion and Criteria for the Classification of Pathological (p) T4 Staging in Colorectal Carcinoma: Confusions, Controversies and Criticisms

Transmural spread by colorectal carcinoma can result in tumor invasion of the serosal surface and, hence, more likely dissemination within the peritoneal cavity and potentially to additional metastatic sites. The adverse prognostic significance of serosal invasion is widely accepted and its presence may be considered an indication for chemotherapy in patients with node negative disease. However, controversy persists regarding the most appropriate criteria for diagnosis and there are also practical difficulties associated with histological assessment in some cases. Therefore, serosal invasion may be under-diagnosed in a significant proportion of tumors, potentially leading to sub-optimal treatment of high-risk patients. The examination of multiple microscopic sections combined with ancillary studies such as cytology preparations, elastin stains, and immunohistochemistry may prove beneficial in selected problematic cases, but these are not used routinely. The relative prognostic significance of serosal invasion and of direct tumor spread to other organs, both of which are incorporated within the pT4 category of the AJCC/UICC TNM staging system, remains unclear. Further studies are required to demonstrate whether recent adjustments to the TNM staging of pT4 tumors are appropriate.

Extended surgery and pelvic exenteration for locally advanced rectal cancer. What are the limits?

Historically, locally advanced rectal cancers with invasion of tumor into adjacent organs (T4 N1, 2 tumors) have been considered poor prognosis cancers treated with palliative intent. However with the advent of multi-modality therapy and improvement in surgical reconstructive techniques, extended resections for rectal tumors are possible with acceptable patient morbidity and excellent oncological outcomes.

EGFR and HER3 mRNA expression levels predict distant metastases in locally advanced rectal cancer

Aberrant activation of the HER signaling pathways plays a critical role in the invasive and metastatic potential of tumors. The aim of this study was to address whether, in rectal cancer, alterations of these pathways could have a value as prognostic factors to be used to identify patients who are at risk of distant metastases. Therefore, the mRNA expression of the four members of the HER family as well as the frequency of PTEN allelic loss and KRAS/BRAF mutations were determined in pretreatment biopsies from a series of 100 locally advanced rectal cancers and then their ability to predict distant metastases was evaluated. Over-expression of EGFR (p = 0.021), HER2 (p = 0.011) and HER3 (p = 0.020) was significantly associated with worse metastasis-free survival in univariate analysis. In multivariate analysis, both over-expression of EGFR (p = 0.028) and HER3 (p = 0.011) remained independent prognostic factors for distant metastasis. In conclusion, quantification of EGFR and HER3 mRNA expression in pretreatment biopsies may be useful to identify patients who are at risk of developing metastases.

Hepatocellular carcinoma: consensus recommendations of the National Cancer Institute Clinical Trials Planning Meeting

Hepatocelluar carcinoma (HCC) is the most common primary malignancy of the liver in adults and the third most common cause of cancer death worldwide. The incidence of HCC in the United States is rising steadily because of the prevalence of hepatitis C viral infection and other causes of hepatic cirrhosis. The majority of patients have underlying hepatic dysfunction, which complicates patient management and the search for safe and effective therapies. The Clinical Trials Planning Meeting (CTPM) in HCC was convened by the National Cancer Institute's Gastrointestinal Cancer Steering Committee to identify the key knowledge gaps in HCC and define clinical research priorities. The CTPM structured its review according to current evidence-based treatment modalities in HCC and prioritized the recommendations on the basis of the patient populations representing the greatest unmet medical need.

'Evidence-based medicine: the time has come to set standards for staging'. Is a radical overhaul really needed?

This Invited Response addresses concerns and opinions expressed in an Invited Commentary, 'Evidence-based medicine: the time has come to set standards for staging', by Quirke et al., published in this issue of The Journal of Pathology.

Revised TN categorization for colon cancer based on national survival outcomes data

PURPOSE

The sixth edition of American Joint Committee on Cancer (AJCC) Cancer Staging Manual for colon cancer subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III because of improved survival for T1-2N2 versus T3-4N2 and T4N1 survival was more similar to T3-4N2 than to T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion and nodal status interact to affect survival.

PATIENTS AND METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 109,953 colon cancer patients were compared with National Cancer Data Base (NCDB) data on 134,206 patients. T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of involved positive lymph nodes (N+): N1a/N1b (1 v 2-3), N2a/N2b (4 to 6 v > or = 7). Five-year observed and relative survival data were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2,T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2ahave similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is betterthan T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based colon cancer analysis is highly consistent with rectal cancer pooled analysis and SEER rectal cancer analyses, supporting the shift of T1-2N2 lesions from IIIC to IIIA/IIIB, shifting T4bN1 from IIIB to IIIC, subdividing T4/N1/N2, and revising substaging of stages II/III. Survival outcomes by TN category for colon and rectal cancer are strikingly similar.