Biomedical subjects

Lars A Akslen

Publications and source records attributed to Lars A Akslen.

38 records · Page 3Linked to original sources

PubMed2002

Can we rely on pathologic parameters to define conservative treatment of papillary thyroid carcinoma?

Papillary thyroid carcinoma is the most common malignant tumor of the thyroid and usually behaves in an indolent fashion. At most institutions these tumors are treated by near-total or total thyroidectomy followed by radioactive iodine ablation. The 2 main reasons for this extensive treatment include high rate of multicentricity in papillary carcinoma and difficulty in ablating large thyroid remnants with radioactive iodine after partial thyroidectomy. Some authors believe, however, that this treatment protocol may not be justified in all cases of papillary carcinoma. We analyzed 253 total thyroidectomies performed for papillary thyroid carcinoma for the following pathologic variables: tumor size, presence of tumor capsular and/or vascular invasion, intrathyroidal spread, tumor in the contralateral lobe, and lymph node metastases. Tumors measuring less than 1 cm and those with extrathyroidal soft tissue extension were excluded from this study. Among 253 cases (197 females, 56 males, age range 14-88 years), the primary tumor size ranged from 1-9.5 cm; 162 cases were completely encapsulated. Tumor capsule invasion was seen in 139 (86%) and vascular invasion was present in 32 (13%) cases; of these 27 (11% of the total) patients showed both tumor capsule and vascular invasion. Seventy-four (29%) patients showed tumor in the contralateral lobe; in 35 (47%) of these cases the contralateral tumor measured less than 1.0 cm. Lymph nodes were sampled in 106 cases, metastases were present in 67 (67/106 = 63%) and only 16 cases with lymph node metastases showed contralateral tumors. No significant correlation was noted between tumor size, occurrence of contralateral tumors, and lymph node metastases. Seventy-one percent of cases included in this study failed to show contralateral tumors. Hence, pathologic parameters such as lack of vascular invasion and lack of multifocality may be used to identify patients who can benefit from conservative therapy alone.

Adolescent↗

PubMed2002

Loss of hMSH2 and hMSH6 expression is frequent in sporadic endometrial carcinomas with microsatellite instability: a population-based study.

Microsatellite instability (MSI) seems to be important in the development of various human cancers including sporadic endometrial cancer. It has previously been shown that alterations in the mismatch repair gene hMLH1 seem to be important for the development of MSI in these tumors. The role of the other mismatch repair genes hMSH2 and hMSH6 has been less well studied, but investigations on patients with hereditary nonpolyposis colorectal cancer indicate that these genes also may be involved. We therefore wanted to investigate the pattern of hMSH2 and hMSH6 expression in a prospective and population-based series of endometrial carcinomas with known hMLH1 expression and MSI status. A total of 138 patients were studied, and pathological staining was seen in 19 cases (14%) for hMLH1, 26 cases (19%) for hMSH2, and 17 cases (12.3%) for hMSH6. Pathological hMLH1 expression was more frequent among tumors with high MSI (those positive for four to five of five markers), whereas pathological expression of hMSH2 and hMSH6 was more frequent among tumors with intermediate MSI (those positive for two to three of five markers). MSI was significantly correlated with pathological expression of hMLH1 (P < 0.001), hMSH2 (P = 0.04), and hMSH6 (P = 0.001). In the group with high MSI, 14 of 16 tumors (88%) showed pathological expression for at least one of the markers. The expression of hMLH1, hMSH2, or hMSH6 did not significantly influence survival. In conclusion, pathological expression of hMLH1 does not seem to account for all tumors with a MSI-positive phenotype in this population-based series of endometrial carcinomas. Our data indicate that the other mismatch repair genes hMSH2 and hMSH6 are also involved, especially in cases with intermediate MSI.

Adaptor Proteins, Signal Transducing↗