Recurrence and Postoperative Death in Patients with Colorectal Cancer: A New Perspective via Semi-competing Risk Framework

BACKGROUND/AIMS

Cancer studies suffer from an overestimation of prediction of survival when both recurrence and death are of interest. This longitudinal study aimed to mitigate this problem utilizing a semi-competing risk approach evaluating the factors affecting recurrence and postoperative death in patients with colorectal cancer.

MATERIALS AND METHODS

This longitudinal prospective study was conducted in 284 patients with resected colorectal cancer who were referred to the Imam Khomeini Clinic in Hamadan, Iran, during 2001-2017. Primary outcomes were postoperative outcomes and patient survival, including time to recurrence (of colorectal cancer), time to death, and time to death after recurrence. All patients who were alive at the end of the study were censored for death and who did not experience recurrence of colorectal cancer were also censored for recurrent colorectal cancer. The relationship between underlying demographics and clinical factors and the outcomes was assessed using a semicompeting risk approach.

RESULTS

The results of the multivariable analysis showed that having metastasis to other sites (hazard ratio = 36.03; 95% CI = 19.48- 66.64) and higher pathological node (pN) stage (hazard ratio = 2.46; 95% CI = 1.32-4.56) were associated with a raised hazard of recurrence. The fewer chemotherapies (hazard ratio = 0.39; 95% CI = 0.17-0.88) and higher pN stages (hazard ratio = 4.32; 95% CI = 1.27-14.75) showed significantly higher hazards of death without recurrence. Having metastasis to other sites (hazard ratio = 2.67; 95% CI = 1.24-5.74) and higher pN stages (hazard ratio = 1.91; 95% CI = 1.02-3.61) were linked with the higher hazard of death after recurrence.

CONCLUSION

Considering findings on death /recu rrenc e-spe cific predictors obtained in this study to manage the outcomes in patients with colorectal cancer, tailored strategies for preventive and interventional plans should be deliberated.

Serum biomarkers of papillary thyroid cancer

Objective

To identify serum biomarkers of papillary thyroid cancer.

Methods

Prospective analysis was performed of banked tumor and serum specimens from 99 patients with thyroid masses. Enzyme-linked immunosorbent assay (ELISA) was employed to measure levels of five serum proteins previously demonstrated to be up-regulated in papillary thyroid cancer (PTC): angiopoietin-1 (Ang-1), cytokeratin 19 (CK-19), tissue inhibitor of metalloproteinase-1 (TIMP-1), chitinase 3 like-1 (YKL-40), and galectin-3 (GAL-3). Serum levels were compared between patients with PTC and those with benign tumors.

Results

A total of 99 patients were enrolled in the study (27 men, 72 women), with a median age of 54 years. Forty-three patients had PTC and 58 cases were benign tumors. There were no statistically significant differences when comparing all five different biomarkers between PTC and other benign thyroid tumors. The p-values were 0.94, 0.48, 0.72, 0.48, and 0.90 for YKL-40, Gal-3, CK19, TIMP-1, and Ang-1, respectively.

Conclusion

Serum levels of four of the five proteins were elevated in patients with thyroid masses relative to normal values. However, the difference between benign and PTC was not significant. Two of the markers (Gal-3 & TIMP-1) displayed a greater potential difference, which may warrant further investigation. This study suggests that other serum markers should be sought. This is the first study to investigate potential serum biomarkers based on over-expressed proteins in thyroid cancer versus benign pathology.

Double fat plane of the radial forearm free flap and its implications for the microvascular surgeon

OBJECTIVE

The radial forearm free flap (RFFF) is a workhorse in reconstruction of head and neck defects. The superficial cephalic vein is used most commonly for microvascular anastomosis; however, this vein has a variable course in the subcutaneous tissues. We have routinely isolated the cephalic vein within a reliable double fat plane, which has not been previously described. This study demonstrates the consistency of the cephalic vein within this double fat plane using a cadaveric model and our prospective operative experience raising the RFFF.

METHOD

Four lightly preserved cadavers and one fresh cadaver were dissected by elevating a RFFF, identifying the double fat plane, and isolating the cephalic vein within this plane. Between August 2006 and April 2008, we prospectively recorded the anatomic location of the cephalic vein in 35 patients who had RFFF surgery.

RESULTS

The double fat plane and cephalic vein were identified in all cadaveric dissections. The double fat plane was identified and led to injury-free dissection of the cephalic vein in all 35 patients.

DISCUSSION

To our knowledge, this is the first report of the presence of the double fat plane within the subcutaneous tissue of the radial forearm and its use as a consistent landmark in finding the cephalic vein. Our cadaveric studies and operative observations have demonstrated that the double fat plane is a reliable, consistent, and helpful guide for the isolation of the cephalic vein in RFFF surgery.