Leiomyosarcoma of the uterus: A clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 49 cases

Evaluation of putative molecular biomarkers in abdominal and retroperitoneal leiomyosarcomas

AIMS

Leiomyosarcomas (LMS) are diverse tumours with different biological behaviour. To evaluate the biological nature of intraabdominal and retroperitoneal leiomyosarcomas we retrospectively examined the immunoreactivity of p53, bcl-2 and proliferative activity expressed as Ki-67-labelling index in 43 tumours.

METHODS

Immunohistochemical staining was performed using a peroxidase-streptavidin method on paraffin-embedded sections using specific anti- p53, anti- bcl-2 and anti Ki-67 monoclonal antibodies.

RESULTS

Of 43 tumours, seven were located in the stomach, 11 in the small or large bowel, 12 in the uterus, 11 in the retroperitoneum and two cases in the urinary bladder. Five-year disease-free survival was 46.5%. Twenty-three patients (53.4%) died of the disease. Positive immunoreactivity for p53 and bcl-2 was found in 18 (41.9%) and 26 patients (60.5%), respectively. Positive Ki-67 staining was observed in eight patients (18.6%). Proliferative indices were higher in LMS with high mitotic activity (P=0.004) and high grade (P=0.009). All Ki-67 positive LMS were intermediate or high-grade tumours. Ki-67-labelling index showed inverse relationship to bcl-2 expression. A trend towards higher survival and expression of bcl-2, p53 or Ki-67 was found.

CONCLUSIONS

Our results demonstrate that p53 and bcl-2 are expressed in a substantial number of intraabdominal and retroperitoneal leiomyosarcomas. In our study, the expression of these biomarkers did not predict patient outcome. Higher Ki-67 labelling indices were found in more biologically aggressive leiomyosarcomas.

Molecular basis of gynecological cancer

Alterations in the cellular genome affecting the expression or function of genes controlling cell growth and differentiation are considered to be the main cause of cancer. Genes that cause cancer are of two distinct types: oncogenes and onco-suppressor genes. The normal proto-oncogene can be converted into an active oncogene by deletion or point mutation in its coding sequence, gene amplification, and by specific chromosome rearrangements. Mutations and abnormal expression in ras, myc, c-erbB-2, and other oncogenes have been reported in several types of gynecological cancer. Onco-suppressor genes are involved in gynecological cancer, their functions are localized in different phases of the cell cycle. Structural changes and deletions of these genes can cause cancer. Mutations in the p53, BRCA1, DCC, and PTEN genes have been reported in gynecological cancers such as ovarian, cervical, and endometrial cancer. Human papillomaviruses are of major interest because specific types (HPV-16, -18, and several others) have been identified as causative agents in at least 90% of cancers of the cervix. In this study we summarize the available information regarding the implication of specific oncogenes, onco-suppressor genes, and HPV in the development of female genital malignancies.

Uterine smooth muscle tumors: utility of classification by proliferation, ploidy, and prognostic markers versus traditional histopathology

CONTEXT

Accurate categorization of uterine smooth muscle neoplasms by light microscopic examination is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. Multiple ancillary techniques have been tested for their ability to predict behavior of uterine smooth muscle tumors.

OBJECTIVE

We assayed 45 smooth muscle neoplasms for a variety of proliferation markers, oncogene protein products, and DNA ploidy level to determine if these markers supplied prognostically useful information over and above that obtained by routine light microscopic assessment.

STUDY DESIGN

Forty-five uterine smooth muscle neoplasms were assessed for DNA ploidy; silver-staining nucleolar organizer regions (AgNORs); percent nuclear proliferating cell nuclear antigen (PCNA); expression of p53, Her-2/neu, and MDM-2 protein; mitotic rate; and nuclear grade. These markers were correlated with histologic diagnosis and the occurrence of a clinically adverse event (death, metastasis, or recurrence).

RESULTS

Diagnostic category (P <.001), nuclear grade (P <.002), mitotic activity (P <.001), mean AgNORs (P <.001), percent nuclear PCNA (P =.02), and expression of p53 (P =.02) all correlated with clinical outcome. No statistically significant correlation between clinical outcome and the categories MDM-2 expression, Her-2/neu expression, or DNA ploidy was seen. Nuclear grade, p53 expression, mitotic rate, AgNORs, and percent nuclear PCNA correlated with diagnosis.

CONCLUSIONS

Diagnostic category, mitotic rate, AgNOR counts, PCNA, and p53 expression dichotomized uterine smooth muscle neoplasms into prognostically favorable and unfavorable groups. Although highly significant, the category AgNORs was no more successful than mitotic rate in dividing uterine smooth muscle neoplasms into prognostically favorable and unfavorable groups. Expression of p53 and percent nuclear PCNA dichotomized uterine smooth muscle neoplasms into prognostic groups, but neither technique reached the level of significance achieved by mitotic rate. Our data indicate that mitotic rate and the classification system of Kempson and Bari are at least as effective as the tested markers in separating uterine smooth muscle neoplasms into prognostic categories.

Leiomyosarcoma of the uterus: a clinicopathologic multicenter study of 71 cases

OBJECTIVE

The aim of this study was to evaluate the behavior of uterine leiomyosarcomas in relation to their clinical and pathologic features and to identify possible prognostic factors.

METHODS

Seventy-one patients with histologically proven uterine leiomyosarcoma were included in the analysis. Leiomyosarcomas were defined as uterine smooth-muscle tumors with five or more mitoses per 10 high-power fields and cytologic atypia. Cox proportional hazards regression model was used to identify independent prognostic factors.

RESULTS

The median follow-up time was 108 months; 5-year overall survival rate was 65%. Evaluating the correlation between several clinicopathologic parameters, tumors with vascular space involvement had a statistically significantly higher stage than tumors without vasular space involvement (P = 0.015). In a univariate Cox model early tumor stage (P < 0.0001), age <50 years (P < 0.0001), low mitotic count (P = 0.05), and the absence of vascular space involvement (P < 0.0005) were associated with good prognosis. In a multivariate analysis age (P = 0.002), tumor stage (P = 0.004), vascular space involvement (P = 0.003), and mitotic count in stage I tumors (P = 0.002) were found to be independent parameters for good prognosis in patients with uterine leiomyosarcoma.

CONCLUSION

Early tumor stage, age <50 years, and absence of vascular space involvement were independently associated with good prognosis. Mitotic count was detected to be a strong prognostic parameter in early tumor stage, but failed to act as an independent prognostic parameter in patients with tumor stage II-IV disease.

Leiomyosarcoma of soft tissue in children: clinicopathologic analysis of 20 cases

Leiomyosarcoma in the pediatric age group is uncommon and incompletely characterized. A series of 20 primary leiomyosarcomas of soft tissue occurring in children younger than 16 years is presented. No significant gender predilection was observed (11 girls and 9 boys). Patient age ranged from 4 to 15 years (median, 12 years). Tumor size ranged from 0.5 to 13 cm (median, 2.5 cm); subcutaneous and deep locations were equally represented. Tumors were evenly distributed among the trunk (30%), head and neck (25%), lower limbs (25%), and upper limbs (20%). All lesions showed at least focally typical features of smooth muscle differentiation, principally in the form of fascicles of eosinophilic spindle cells with cigar-shaped nuclei. An unusual whorled growth pattern was seen in two cases. Morphologic variants including inflammatory leiomyosarcoma (one case), granular cell leiomyosarcoma (two cases), giant-cell rich leiomyosarcoma (two cases), and epithelioid leiomyosarcoma (one case) were seen. Dystrophic calcifications were present in two cases. Most lesions (85%) were low grade. Immunohistochemical staining showed positivity for alpha-smooth muscle actin in 89% of the cases, HHF-35 in 87%, and desmin in 61%. Positivity for cytokeratins, observed in 6 (43%) of 14 cases tested, was usually strong and was diffuse in two cases. Follow-up data, available in 15 (75%) patients (median duration, 49 months), showed late local recurrence in only two cases, one with progression to a higher grade lesion, and no metastasis. These results show that, although extremely rare, soft-tissue leiomyosarcomas do occur in children, in whom they usually present as small morphologically low-grade lesions that seem to behave in a relatively indolent fashion, although longer follow-up data are needed. Differential diagnosis in this setting includes infantile myofibromatosis, leiomyoma, monophasic synovial sarcoma, and spindle cell rhabdomyosarcoma.

Endometrial stromal sarcoma of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 17 cases

Seventeen patients with endometrial stromal sarcoma (ESS) diagnosed between 1970 and 1996 were evaluated according to DNA ploidy, S-phase fraction (SPF), p53, and mdm-2 expression, as well as traditional clinical and pathologic prognostic factors, such as tumor stage, grade, and mitotic index. DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors. Flow cytometric DNA histograms were obtained from 16 patients. The patients ranged in age from 41 to 78 years (median, 57 years). Seven (41%) patients were premenopausal. Thirteen low-grade ESS were DNA diploid and had a low SPF. Of these, two overexpressed p53, while only one was mdm-2 positive. Among the four high-grade ESS we found one (25%) DNA diploid tumor and three (75%) DNA aneuploid tumors. Two (50%) had an SPF greater than 10%, three (75%) were p53-positive, and two (50%) overexpressed mdm-2. During the observation period, nine (53%) patients (five with low-grade and four with high-grade tumors) died of disease. The 5-year survival rate for patients with low-grade ESS was 74%, while all four patients with high-grade ESS died of disease within 14 months of diagnosis. Using the log-rank test, we found a significant correlation between survival and tumor grade (P = 0.007), DNA ploidy (P = 0.026), SPF (P = 0.048), and FIGO surgical stage (P = 0.026). In conclusion, we found that tumor grade was a strong predictor of clinical outcome in ESS. In addition, a worse prognosis was found for those ESS patients with advanced disease, DNA aneuploidy, and a high SPF. There was no difference between the recurrent and nonrecurrent group of early stage (surgical stage I), low-grade ESS with regard to clinicopathological features, DNA ploidy, SPF, p53, and mdm-2 expression. All patients with high-grade ESS died of disease within 14 months of diagnosis. In contrast, only three of the 11 patients with early stage, low-grade ESS died of disease.

Adenosarcoma of the uterus: a clinicopathologic, DNA flow cytometric, p53 and mdm-2 analysis of 11 cases

Eleven patients with uterine adenosarcoma diagnosed between 1970 and 1995 were evaluated according to DNA ploidy, S-phase fraction, p53 and mdm-2 expression, and traditional clinical and pathological prognostic factors, such as tumor stage, grade and mitotic index. DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors. The patients ranged in age from 41 to 90 years (median, 76 years). Only one patient was premenopausal at the time of diagnosis and five (45%) were nulliparous. One patient had received previous pelvic irradiation for anal squamous carcinoma. Six of the tumors (55%) were pure adenosarcoma and five (45%) were adenosarcoma with sarcomatous overgrowth. Nine patients had a stage I tumor and two had a stage II tumor. Among the six adenosarcomas we found three DNA diploid tumors, two DNA aneuploid tumors, and one DNA multiploid tumor. All adenosarcomas had an S-phase fraction less than 10%, except one that was not assessable. None was p53 positive and only one overexpressed mdm-2. All five adenosarcomas with sarcomatous overgrowth were DNA aneuploid, three (60%) had an S-phase fraction > 10%, two (40%) were p53 positive, and one (20%) overexpressed mdm-2. Five of the eleven patients suffered recurrences, and three (60%) of these developed lung metastases. During the observation period four (36%) patients (2 adenosarcomas and 2 adenosarcoma with sarcomatous overgrowth) died of disease, three patients died of intercurrent disease without recurrence, and the remaining four are alive with no evidence of disease. The overall five-year survival rate for all stages was 69%; for patients with AS it was 80%, while for those with adenosarcoma with sarcomatous overgrowth it was 50%. There were no variables which correlated with survival. In conclusion, we found hat the typical adenosarcoma had a tendency to be of low stage, have a lower mitotic rate and an S-phase fraction <10%. On the other hand, adenosarcomas with sarcomatous overgrowth were of high grade, had a high mitotic rate, and were DNA aneuploid with an S-phase fraction >10%. None of the variables studied correlated with survival. Tumors that were p53-positive or overexpressed mdm-2 did not behave worse than their negative counterpart. All patients who recurred with distant metastases died of disease.