Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)
The chronic myeloproliferative disorders consist of chronic myelogenous leukemia, polycythemia vera (p. vera), primary myelofibrosis, essential thrombocythemia, chronic neutrophilic leukemia, and chronic eosinophilic leukemia. All of these disorders involve dysregulation at the multipotent hematopoietic stem cell (CD34), with one or more of the following shared features:
Overproduction of one or several blood elements with dominance of a transformed clone.
Hypercellular marrow/marrow fibrosis...
Stage II seminoma is divided into bulky and nonbulky disease for treatment planning and expression of prognosis. Bulky disease is generally defined as tumors larger than 5 cm on a computed tomographic (CT) scan (i.e., stage IIC disease). Nonbulky disease can be further subdivided into stage IIA, meaning no lymph node mass larger than 2 cm, and stage IIB, meaning a lymph node mass between 2 cm and 5 cm.
Nonbulky stage II disease has a cure rate of about 90% to 95% with radiation alone at doses of 30 Gy to 36 Gy, [1,2,3,4] and most relapsing patients can be cured with chemotherapy. Cure rates are slightly higher for patients with stage IIA disease than for those with IIB disease, but the figures are within the range given above. Risk factors for relapse include multiple enlarged nodes.
Results for patients with stage IIC disease have been less favorable. For example, one institution reported that 9 of 16 (56%) stage IIC patients relapsed following radiation therapy, while relapse occurred in only 1 of 23 (4%) IIC patients treated with chemotherapy. A pooled analysis of earlier studies reported a 65% relapse-free survival for men receiving radiation therapy for bulky stage II seminoma. Unfortunately, there are only sparse contemporary data on the use of radiation therapy to treat bulky stage II seminomas, and there are no randomized trials comparing radiation therapy with chemotherapy in this population. Combination chemotherapy with cisplatin is effective therapy in patients with bulky stage II seminomas and has become the most widely accepted treatment option.[6,7]
Residual radiologic abnormalities are common at the completion of chemotherapy. Many abnormalities gradually regress over a period of months. Some clinicians advocate empiric attempts to resect residual masses 3 cm or larger, while others advocate close surveillance, with intervention only if the residual mass increases in size. Postchemotherapy radiation therapy has fallen out of favor, in part because of a retrospective study of a consecutive series of 174 seminoma patients with postchemotherapy residual disease seen at ten treatment centers that reported that empiric radiation was not associated with any medically significant improvement in progression-free survival after completion of platinum-based combination chemotherapy.[Level of evidence: 3iiDiii]
In some series, surgical resection of specific masses has yielded a significant number of patients with residual seminoma who require additional therapy. Nevertheless, other reports indicate that the size of the residual mass does not correlate well with active residual disease, most residual masses do not grow, and frequent marker and CT scan evaluation is a viable option even when the residual mass is 3 cm or larger.