Pathologic analysis of advanced adult soft tissue sarcomas, bone sarcomas, and mesotheliomas. The eastern cooperative oncology group (ECOG) experience

Abstract

A total of 488 tumors entered in the Eastern Cooperative Oncology Group (ECOG) Study EST 3377 were evaluated histologically by a panel of pathologists from member institutions for quality control purposes. The overall agreement rate between the eligible submitting diagnosis and the pathology review panel's diagnosis was 74% (312/424). In 10% (44/424), the case was excluded because it was deemed to be nonsarcoma. In the other 16%, the disagreement concerned the type of sarcoma. The histologic type with the lowest agreement rate was rhabdomyosarcoma (17%), followed by sarcoma not otherwise specified (NOS) (27%), angiosarcoma (33%), and fibrosarcoma (48%). These figures reflect the significant degree of difficulty in the diagnosis of these tumor types. The treatment response rate of soft tissue sarcomas in the randomized study of Adriamycin (Adria Laboratories, Columbus, OH) regimens was slightly higher for those with lower grade sarcomas, i.e., 25% (four of 16) response rate for Grade 1 lesions; 22% (17/77) for Grade 2, and 21% (35/170) for Grade 3. When adjusted for type of sarcoma, there was no noticeable difference between Grade 1-2 versus 3 in response rate. A statistically significant difference in the percentage of complete responders was noted between Group A tumors (synovial sarcoma, hemangiopericytoma, sarcoma NOS, and Ewing's; 12.2%) versus Group B tumors (all other types--mostly spindle cell sarcomas; 3.5%) (P = 0.02).

Soft Tissue Sarcomas

“…Certain tumors have an assigned grade based on the histologic diagnosis (eg, Grade 1 for well-differentiated liposarcomas; Grade 3 for rhabdomyosarcoma). Sarcomas may be misdiagnosed or misclassified by the general pathologist in up to 25% to 40% of cases; [21][22][23][24] therefore, it is strongly recommended that cases be reviewed before therapy by experts in sarcoma pathology. This high rate of discordance illustrates the need for more objective molecular and biochemical markers to improve the accuracy of conventional histologic assessments.…”

Sarcomas in north west England: I. Histopathological peer review

“…

The consequences of some of these problems are exemplified in the results of the peer review studies of sarcomas which have been undertaken (Baker et al, 1978;Presant et al, 1986;Newton et al, 1988;Shiraki et al, 1989;Alvegard & Berg, 1989). In these series histological sub-type of sarcoma was frequently changed on review and significant proportions of tumours were considered ineligible as sarcomas.

The study undertaken here was an attempt to define accurately the incidence of sub-types of sarcomas Grade of malignancy was not specified but in smooth muscle tumours where malignancy was equivocal, mitotic counts were performed using the criteria for malignancy recommeded by Enzinger and Weiss (1988).

…”

“…The consequences of some of these problems are exemplified in the results of the peer review studies of sarcomas which have been undertaken (Baker et al, 1978;Presant et al, 1986;Newton et al, 1988;Shiraki et al, 1989;Alvegard & Berg, 1989). In these series histological sub-type of sarcoma was frequently changed on review and significant proportions of tumours were considered ineligible as sarcomas.…”

Management of angiosarcoma

“…Because angiosarcoma is not among the more common subtypes of soft tissue sarcoma, it is often difficult to determine the responsiveness of this tumor in large chemotherapy trials enrolling patients with soft tissue sarcomas. In a review of the pathologic diagnoses of patients enrolled in a sarcoma trial performed by the Eastern Cooperative Oncology Group (ECOG), angiosarcoma was the diagnosis on protocol entry for only nine of 488 patients entered between November 1977 and February 1983 [12]. Furthermore, only four cases were confirmed to have a diagnosis of angiosarcoma by the pathology review panel [12], demonstrating both the rarity of the disease and the difficulty of reproducible diagnosis in these patients.…”

“…In a review of the pathologic diagnoses of patients enrolled in a sarcoma trial performed by the Eastern Cooperative Oncology Group (ECOG), angiosarcoma was the diagnosis on protocol entry for only nine of 488 patients entered between November 1977 and February 1983 [12]. Furthermore, only four cases were confirmed to have a diagnosis of angiosarcoma by the pathology review panel [12], demonstrating both the rarity of the disease and the difficulty of reproducible diagnosis in these patients. Angiosarcoma, then, was included in the "all others" category, in which a response rate of 22% was observed in patients treated with doxorubicin with or without dacarbazine, similar to the response rate in the trial overall [13].…”