Prognostic value of ploidy, cell proliferation kinetics, and conventional clinicopathologic criteria in patients with colorectal carcinoma: a prospective study

DNA ploidy status and prognosis in colorectal cancer: a meta-analysis of published data

PURPOSE

In colorectal cancer, the negative effect of aneuploidy has been a controversy for more than 20 years. Studies to determine a survival-deoxyribonucleic acid content relationship have conflicting results. A systematic literature search followed by a meta-analysis of published studies addressing prognostic effect of aneuploidy for patients who underwent surgical treatment of colon and rectal cancer was conducted.

METHODS

The main outcome measure was the five-year overall mortality rate after surgical resection. For the selected studies, we estimated this outcome for three subsets of patients through separate meta-analyses: 1) for all patients with colorectal cancer; 2) only between patients with Stage II colon cancer; and 3) only for studies in which follow-up losses were declared. The presence of publication bias was assessed with a funnel plot for asymmetry.

RESULTS

A total of 5,478 patients with colorectal cancer were represented in 32 studies (Group 1), we estimated a reduction in the five-year overall mortality from 43.2 percent for aneuploid tumors to 29.2 percent for diploid tumors (combined relative risk = 1.44; 95 percent confidence interval = 1.34-1.55; P < 0.001). In addition, 357 patients with Stage II colon cancer (Group 2) extracted from three studies had an absolute reduction of 14.3 percent in five-year overall mortality favoring diploid tumors (combined relative risk = 1.93; 95 percent confidence interval = 1.29-2.89; P = 0.001). Lastly, of 14 studies in which follow-up losses were declared (Group 3), 2,221 patients were represented and a 15.7 percent mortality reduction was measured favoring patients with diploid tumors (combined relative risk = 1.44; 95 percent confidence interval = 1.3-1.61; P < 0.001).

CONCLUSIONS

Patients who undergo an aneuploid colorectal cancer surgical resection have a higher risk of death after five years. This finding may ultimately impact survival of patients with node-negative colon cancer through adjuvant therapy.

Molecular prognostic markers in resectable colorectal liver metastases: A systematic review

BACKGROUND

Determination of prognosis in patients with resectable colorectal liver metastases (CLM) is desirable in order to improve case selection for surgery and tailor adjuvant treatment according to individual recurrence risk. Conventional clinicopathological factors lack the sensitivity to accurately achieve this goal. Consideration of tumour biology and the identification of molecular prognostic markers may allow more accurate risk stratification.

METHOD

This systematic review examines evidence from published manuscripts looking at molecular markers in resectable colorectal liver metastases and their correlation with disease recurrence and survival following hepatectomy.

RESULTS

Studies have yielded promising results in the search for prognostic molecular markers of CLM. Molecular biomarkers from varied aspects of tumour biology have been examined and a number of these, including proliferation indices, telomerase, thymidylate synthase, microvessel density and thrombospondin-1 appear to have prognostic utility in this context. Validation of other markers, notably p53, has been limited by a failure of methodologies to account for their biological complexity.

CONCLUSIONS

A biomarker-based approach may yield significant benefits through informed treatment of resectable metastatic colorectal malignancy. Standardised retrospective analyses are necessary to confirm preliminary findings and identify existing and novel markers for inclusion into prospective studies. Assessment and verification of multiple molecular markers in this manner may allow molecular profiling of metastases and tailoring of therapy according to the biological aggressiveness of individual tumours. The advent of genomic- and proteomic-based technologies will allow the simultaneous analysis of multiple molecular markers and the derivation of disease profiles associated with disease recurrence and poor survival.

Stratifying risk factors for follow-up: a comparison of recurrent and nonrecurrent colorectal cancer

INTRODUCTION

The selection of patients for individualized follow-up and adjuvant therapy after curative resection of colorectal carcinoma depends on finding reliable prognostic criteria for recurrence. However, such criteria are not universally accepted, and follow-up is often standardized for all patients without regard for each individual's level of risk of recurrence. Such a system of follow-up is not cost-effective.

METHODS

A comparison of operative findings, pathologic features, and follow-up data of 1,731 cases of nonrecurrent colorectal cancer (821 colon, 910 rectum) with 357 cases of recurrent colorectal cancer (164 colon, 193 rectum) following potentially curative surgery was made, and results were analyzed to ascertain criteria for stratifying follow-up according to risk factors.

RESULTS

Single-factor analysis showed that Dukes staging and tumor invasion were significantly associated with recurrence in both rectal and colon carcinoma. Tumor fixation and grading were additional significant factors in rectal cancer. Recurrence rates, time to recurrence, site of recurrence (locoregional vs. distant), and pattern of metastatic spread were not significantly affected by original tumor site. Recurrence was not significantly affected by patient age and gender. Individual surgeon performance in this series had also no significant effects on tumor recurrence. With multivariate analysis only, Dukes staging and tumor invasion into adjacent tissues were found to be independent adverse prognostic factors for recurrence.

CONCLUSIONS

Dukes staging and tumor penetration into adjacent tissues are the only significant adverse prognostic factors for tumor recurrence of colonic and rectal carcinoma. Tumor grade and tumor fixation are additional adverse prognostic factors in rectal cancer. Guidelines for follow-up may be based on these factors and follow-up thus stratified according to risk of developing recurrence.

Delay in the diagnosis and outcome of colorectal cancer: a prospective study

AIMS

The aim of this study was to examine the incidence of the delay in the diagnosis of colorectal carcinoma, possible causes of this delay and its effects on outcome.

METHODS

A prospective study was performed on 100 patients affected by colorectal cancer. Duration of symptoms was calculated from the date of onset of symptoms to the date of surgery.

RESULTS

Sixty-nine patients suffered delays in treatment of more than 12 weeks from the onset of symptoms. In patients with symptoms of less than 12 weeks' duration there was a higher incidence of radical surgery and none of these patients presented, at the time of surgery, a neoplastic dissemination. Multivariate analysis, however, showed that the only factors with an independent effect on 5-year survival and disease-free survival were Dukes' stage and the presence of pre-operative complications.

CONCLUSIONS

The results of this study suggest that, independent of the diagnostic delay, the outcome of the colorectal cancer is only conditioned by tumour stage and by complicated cancer.

Low tumour cell proliferation at the invasive margin is associated with a poor prognosis in Dukes' stage B colorectal cancers

The conflicting results about the prognostic impact of tumour cell proliferation in colorectal cancer might be explained by the heterogeneity observed within these tumours. We have investigated whether a systematic spatial heterogeneity exists between different compartments, and whether the presence of such a systematic heterogeneity has any impact on survival. Fifty-six Dukes' stage B colorectal cancers were carefully morphometrically quantified with respect to the immunohistochemical expression of the proliferative marker Ki-67 at both the luminal border and the invasive margin. The proliferative activity was significantly higher at the luminal border compared with the invasive margin (P<0.001), although the two compartments were also significantly correlated with each other. Tumours with low proliferation at the invasive margin had a significantly poorer prognosis both in univariate (P = 0.014) and in multivariate survival analyses (P = 0.042). We conclude that Dukes' B colorectal cancers exhibit a systematic spatial heterogeneity with respect to proliferation, and tumours with low proliferation at the invasive margin had a poor prognosis. The present data independently confirm recent results from the authors, and provide new insights into the understanding of tumour cell proliferation in colorectal cancer.

Role of follow-up in management of local recurrences of colorectal cancer: a prospective, randomized study

PURPOSE

This prospective, randomized, single-center study was designed to evaluate the influence of follow-up on detection and resectability of local recurrences and on survival after radical surgery for colorectal cancer.

METHODS

Between 1987 and 1990, 207 consecutive patients who underwent curative resections for primary untreated large-bowel carcinoma were randomly assigned to a conventional follow-up group (Group A; n = 103) and to an intense follow-up group (Group B; n = 104). All the patients were followed up prospectively, and the outcome was known for all of them at five years. Patients in Group A were seen at six-month intervals for one year, and once a year thereafter. Patients in Group B were checked every three months during the first two years, at six-month intervals for the next three years, and once a year thereafter.

RESULTS

Of the 103 patients in Group A, local recurrence was detected in 20; 9 (13 percent) of these patients had colon cancer, and 11 (29 percent) had rectal cancer. Of the 104 patients in Group B, local recurrence was detected in 26; 12 (16 percent) of these patients had colon cancer, and 14 (45 percent) had rectal cancer. Twelve cases (60 percent) of local recurrence in Group A and 24 cases (92 percent) in Group B were detected at scheduled visits (P < 0.05). Local recurrences were detected earlier in patients of Group B (10.3 +/- 2.7 vs. 20.2 +/- 6.1 months; P < 0.0003). Curative re-resection was possible in 2 patients (10 percent) in Group A, 1 with colon cancer and 1 with rectal cancer, and in 17 patients (65 percent) in Group B, 6 with colon cancer and 11 with rectal cancer (P < 0.01). Of the Group B patients who had curative re-resections of local recurrence, 8 (47 percent) were disease-free and long-term survivors as of the last follow-up, and 2 (11.7 percent) were alive, but with a new recurrence. The 2 patients in Group A who had curative re-resections died as a result of cancer. The five-year survival rate in Group A was 58.3 percent and in Group B was 73.1 percent. The difference is statistically significant (P < 0.02).

CONCLUSIONS

Our data support use of an intense follow-up plan after primary resection of large-bowel cancer, at least in patients with rectal cancer.

Character of the invasive margin in colorectal cancer: does it improve prognostic information of Dukes staging?

PURPOSE

The clinical significance and prognostic value of the histopathologic parameters used in both the Dukes and Jass classifications were evaluated to select those with an independent effect on survival after radical surgery for colorectal cancer.

METHODS

The depth of local spread (limited to the bowel wall or extended beyond it), the number of metastatic lymph nodes (none, 1-4, more than 4), the character of the invasive margin (pushing or infiltrating), and the presence or absence of conspicuous peritumoral lymphocytic infiltration were assessed in 235 patients who had undergone radical resection for colorectal cancer. The influence of these variables on survival was studied by univariate and multivariate analysis.

RESULTS

No significant difference in survival was found between patients with conspicuous peritumoral infiltrate and those without it; moreover, multivariate analysis failed to show any independent prognostic value for either lymphocytic infiltration or depth of local invasion. However, the character of the invasive margin and the number of metastatic lymph nodes were identified as the only variables with any independent importance on survival. Based on these data, a new prognostic model may be proposed; it uses the character of the infiltrative margin as a discriminating factor among patients within the lymph node-negative (Dukes A and B stages) and lymph node-positive (Dukes C1 and C2 subsets) groups. A good prognosis for Dukes A, B, and C1 patients was associated with pushing tumors; C1 and C2 patients with infiltrating tumors had a poor prognosis. On the whole, the new prognostic model has allowed for the placement of 59.6 percent of our patients into groups that provide a confident prognosis. The clinical outcome of Dukes A and B patients with infiltrating tumors is still uncertain.

CONCLUSIONS

The character of the invasive margin is an important prognostic factor in colorectal cancer. The association of this parameter with the traditional Dukes classification may provide additional useful prognostic information and aid in the selection of those patients who could most benefit from adjuvant therapy.