Contiguous invasion per se does not affect prognosis in colon cancer

Perineural Invasion is a Strong Prognostic Factor in Colorectal Cancer: A Systematic Review

Perineural invasion (PNI) is a possible route for metastatic spread in various cancer types, including colorectal cancer (CRC). PNI is linked to poor prognosis, but systematic analyses are lacking. This study systematically reviews the frequency and impact of PNI in CRC. A literature search was performed using PubMed database from inception to January 1, 2014. Data were analyzed using Review Manager 5.3. A quality assessment was performed on the basis of modified REMARK criteria. Endpoints were local recurrence (LR), 5-year disease-free survival (5yDFS), 5-year cancer-specific survival (5yCSS), and 5-year overall survival (5yOS). Meta-analysis was performed in terms of risk ratios (RR) and hazard ratios (HR) with 95% confidence interval (95% CI). In this meta-analysis, 58 articles with 22,900 patients were included. PNI was present in 18.2% of tumors. PNI is correlated with increased LR (RR 3.22, 95% CI, 2.33-4.44) and decreased 5yDFS (RR 2.35, 95% CI, 1.66-3.31), 5yCSS (RR 3.61, 95% CI, 2.76-4.72), and 5yOS (RR 2.09, 95% CI, 1.68-2.61). In multivariate analysis PNI remains an independent prognostic factor for 5yDFS, 5yCSS, and 5yOS (HR 2.35, 95% CI, 1.97-3.08; HR 1.91, 95% CI, 1.50-2.42; and HR 1.85, 95% CI, 1.63-2.12, respectively). We confirmed the strong impact of PNI for LR and survival in CRC. The prognostic value of PNI is similar to that of well-established prognostic factors as depth of invasion, differentiation grade, lymph node metastases, and lymphatic and extramural vascular invasion. Therefore, PNI should be one of the factors in the standardized reporting of CRC and might be considered a high-risk feature.

Clinical and prognostic significance of pathological and inflammatory markers in the surgical treatment of locally advanced colorectal cancer

Background

Locally advanced colorectal cancer (CRC) may vary in its clinical and pathological appearance. It is now accepted that progression of disease in patients with locally advanced CRC is determined not only by local tumor characteristics but also by the immune system and inflammatory response in the body.

Methods

We investigated patients with confirmed CRC who were treated in the surgical clinic at the University Hospital Alexandrovska over a 10-year period and retrospectively evaluated the histological features of the preoperative biopsies and operative specimens removed during radical multivisceral resections. We also collected prospective data for serum C-reactive protein levels and Jass-Klintrup score, Petersen Index score, and Glasgow Prognostic Score in patients with locally advanced CRC.

Results

Of 1,105 patients with CRC, 327 (29.6%) were diagnosed with locally advanced disease. In total, 108 combined multivisceral resections (79 for primary tumors and 29 for recurrent tumors) were performed. Overall survival was 34 months for pR0 cases and 12 months for pR1 cases (P<0.05). Our data confirmed that C-reactive protein is a prognostic marker of overall survival. Data for 48 patients with histologically confirmed locally advanced tumors showed significantly increased survival with a higher Jass-Klintrup score (P=0.037). In patients with node-negative disease, 5-year survival was 49%. However, where there were high-risk pathological characteristics according to the Petersen Index, survival was similar to that for node-positive disease (P=0.702). Our data also showed a significant difference in survival between groups divided according to whether they had a modified Glasgow Prognostic Score of 1 or 2 (P=0.031).

Conclusion

In order to maintain a reasonable balance between an aggressive approach and so-called meaningless “surgical exorbitance”, we should focus on certain histopathological and inflammatory markers that can be identified as additional factors for planning the type and volume of surgical treatment.

Prognostic value of perineural invasion in colorectal cancer: a meta-analysis

BACKGROUND

The prognostic value of perineural invasion (PNI) in colorectal cancer (CRC) does not reach a consensus.

METHODS

A comprehensive literature search for relevant reports published up to October 2014 was performed using the electronic databases: PubMed, Embase, and Web of Science. The pooled hazard ratio (HR) with 95 % confidence intervals (CI) was used to estimate the prognostic effects.

RESULT

Thirty-eight studies comprising 12,661 CRC patients were analyzed. Our results showed that PNI is significantly associated with poor prognosis in OS (overall survival) (HR = 2.07, 95 % CI = 1.87-2.29, P < 0.01) and DFS (disease-free survival) (HR = 2.23, 95 % CI = 1.79-2.78, P < 0.01). There was no significant prognostic difference in DFS between stage II CRC patients with PNI(+) and stage III patients (HR = 1.67, 95 % CI = 0.53-5.25, P = 0.38). Further subgroup analysis revealed that the significance of the association between PNI and worse prognosis in CRC patients is not affected by many factors, including geographic setting, PNI positive rate, treatment, TNM stage, tumor site, and quality of the study.

CONCLUSIONS

The meta-analysis indicates that PNI is a poor prognostic factor in CRC patients. The postoperative survival of stage II CRC patients with PNI(+) is probably more similar to that of stage III patients. Currently available adjuvant therapy should be considered in stage II CRC patients with PNI(+).

Accuracy of TNM staging in colorectal cancer: a review of current culprits, the modern role of morphology and stepping-stones for improvements in the molecular era

Colorectal cancer (CRC) is the third most common cancer worldwide. Survival is largely stage-dependant, guided by the tumor-node-metastases (TNM) system for TNM assessment. Histopathological evaluation, including assessment of lymph node status, is important for correct TNM staging. However, recent updates in the TNM system have resulted in controversy. A continued debate on definitions resulting in potential up- and downstaging of patients, which may obscure survival data, has led the investigators to investigate other or alternative staging tools. Consequently, additional prognostic factors have been searched for using the regular light microscopy. Among the factors evaluated by histopathology include the evaluation of tumor budding and stromal environment, angiogenesis, as well as involvement of the immune system (including the 'Immunoscore'). We review the current role of histopathology, controversies in TNM-staging and suggested alternatives to better predict outcome for CRC patients in the era of genomic medicine.

Analysis of the seventh edition of American Joint Committee on colon cancer staging

PURPOSE

The seventh edition of the American Joint Committee on Cancer (AJCC) staging system has new substages for colon cancer. We used survival data from a single medical center to analyze this new AJCC edition.

METHODS

The colon cancer database of Taipei Veterans General Hospital provided 1,865 patient records covering from 1999 to 2005. Survival rates were evaluated using the Kaplan-Meier method.

RESULTS

There were 268, 607, 561, and 421 patients in stages I, II, III, and IV disease with 5-year observed survival rates of 86.3%, 79.2%, 65.4%, and 12.8%, respectively. Survival rates were not significantly different between those with T4a and T4b disease (P = 0.806). The outcome of N1c disease was similar to N1a and N1b but worse than N0 (P = 0.004). Survival rates for M1a and M1b disease became different after reclassifying solely peritoneal seeding as M1a (P < 0.001). No discrepancy of outcomes between stage IIIA and stage IIB/IIC remained in the seventh edition.

CONCLUSIONS

Evolution from the fifth to seventh edition of the AJCC staging system is successful in separating prognostic groups by substaging. But some issues remain unresolved, including the subdivision of T4, N1, and M1.

T4N0 colon cancer has oncologic outcomes comparable to stage III in a specialized center

BACKGROUND

National data indicate that patients with T4N0 colon carcinoma have worse oncologic outcomes than other stage II cases. Our hypothesis was that optimized surgical resection and lymph node staging in a specialized center could eliminate discrepancies in oncologic outcomes within stage II colon carcinomas.

METHODS

Patient characteristics and outcomes after oncologically radical colectomy for pT4N0 were compared to control groups of T1-2N1, T3N1, and T3N0 cases. Group comparisons were adjusted for age, American Society of Anesthesiologists score, tumor location, year of surgery, and duration of follow-up. Cases with at least 12 collected lymph nodes and uninvolved resection margins (R0) were analyzed separately. In addition, the T4a subgroup was compared to both T4b cases with involvement of bowel loops and with infiltration of other organs or structures.

RESULTS

T4N0 patients had worse oncologic outcomes than T1-2N1 patients and were comparable to T3N1 patients, regardless of margins status or lymph node collection. When a T4b tumor infiltrated bowel, survival and recurrence rates were similar to T4a cases, while T4b tumors involving other organs were associated with increased recurrence rate and reduced survival.

CONCLUSIONS

T4N0 colon carcinoma remains associated with poor oncologic outcomes, regardless of treatment in a specialized center. The biologic aggressiveness of T4N0 colon cancers and the different oncologic outcomes according to specific organ infiltration should be taken into consideration in the choice of adjuvant therapies.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.