recurrence following hepatectomy for metastatic colorectal cancer: development of a model that predicts patterns of recurrence and survival.

BACKGROUND: While several prognostic models have been developed to predict survival of patients who undergo hepatectomy for metastatic colorectal cancer (mCRC), few data exist to predict survival after recurrence. We sought to develop a model that predicts survival for patients who have developed recurrence following hepatectomy for mCRC. METHODS: A retrospective analysis was performed on data from consecutive patients that underwent hepatectomy for mCRC. Clinicopathologic data, recurrence patterns, and outcomes were analyzed. Kaplan-Meier survival analysis and univariate and multivariate analyses were performed. An integer-based model was created to predict the patterns of recurrence and survival after recurrence. RESULTS: This analysis included 280 patients with a median follow-up of 50.1 months. Of these, 53% underwent major hepatectomy and 87% had negative margins. Recurrent disease developed in 63% of patients. After hepatectomy, factors associated with short disease-free interval (DFI) and overall survival (OS) included CEA > 200 ng/ml (P < 0.0005), >1 metastasis (P < 0.0005), and a high Fong score (P < 0.0005). After recurrence, the pattern of recurrence was a strong predictor of OS (P < 0.0005). Independent predictors of the pattern of recurrence on multivariate analysis include CEA > 200 ng/ml, tumor size >5 cm, and >1 liver metastasis. A simple predictive scoring system was developed from the beta coefficients of this analysis that correlated with recurrence pattern (P < 0.0005). CONCLUSIONS: After hepatectomy, survival of patients with recurrent mCRC is strongly predicted by the patterns of recurrence, and the recurrence pattern can be predicted with a simple model. This can also be extended to create a scoring system that estimates expected survival.

Assessment of mitotic rate reporting in melanoma.

BACKGROUND: In patients with cutaneous melanoma, mitotic rate (MR) historically has been reported as the number of mitoses per high-power field (hpf) or per 10 hpf. The most recent revision of the American Joint Committee on Cancer melanoma staging system now incorporates MR and specifies that MR should be reported as mitoses per mm(2), with a conversion factor of 1 mm(2) equaling 4 hpf. However, because many pathologists continue to report MR in hpf units, we sought to compare the 2 conventions for reporting MR; this is important now that MR is used for staging and prognostic information. METHODS: A retrospective analysis was performed of a database that combined patients from a large multicenter study and our single-institution melanoma database. All patients with pathology reports that included MR were included. For patients with MR reported in hpf units, MR was converted to mitoses per 10 hpf. Statistical analysis was performed to test differences in Breslow thickness (BT), ulceration, sentinel lymph node (SLN) status, and overall survival (OS) (log-rank test) between the mitoses per mm(2) group versus the mitoses per 10-hpf group. RESULTS: A total of 1,148 patients were identified; of these, 759 were reported as per mm(2) and 389 were reported in hpf units. When patients were subdivided into categories of MR of 0, 1, or more than 1, there was no statistically significant difference in mean or median BT, ulceration, or SLN positivity within categories between patients with MR per mm(2) versus patients with MR reported per 10 hpf. There was also no difference in OS between groups. Subdividing into smaller categories of MR of 0, 1, 2, 3, 4, 5, or more than 5 did not yield different results. CONCLUSIONS: Although the American Joint Committee on Cancer staging system reports a conversion factor for MR of 1 mm(2) equals 4 hpf, no clinically meaningful differences in predictors of prognosis (BT, ulceration, SLN positivity) or OS were seen between groups when a conversion factor of 1 mm(2) equaling 10 hpf was used. Therefore, for practical purposes, MR reported per 10 hpf approximates MR per mm(2).