Devita, Hellman, and Rosenberg's Cancer

LWBK1006-19 LWW-Govindan-Review December 7, 2011 21:24

224 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

neuromuscular syndromes (myasthenia gravis, Eaton–Lambert myas-

thenic syndrome, and myotonic dystrophy), hematologic disorders (pure

red cell aplasia, hypogammaglobinemia, T-cell deficiency syndrome, and

amegakaryocytic thrombocytopenia) and miscellaneous disorders (hyper-

trophic pulmonary osteoarthropathy, nephrotic syndrome and paraneo-

plastic pemphigus).

Answer 19.7. The answer is D.

This man presents after incomplete surgical resection of a high-grade

thymic carcinoma. Thymic carcinoma is a rare, aggressive malignancy

that is frequently locally advanced or metastatic at diagnosis. The many

histologic subtypes of thymic carcinoma generally fall into two clinically

relevant categories: low grade or well differentiated (WHO type B3) and

high grade (WHO type C). Low-grade thymic carcinomas can have a rela-

tively indolent course leading to reported median survivals of 25 months

to over 6 years. However, the median survival of patients with high-

grade thymic carcinoma is only 11 to 15 months. Although the rarity of

thymic carcinoma precludes evidence-based treatment guidelines, most

patients undergo multimodality therapy because of the locally invasive

nature of the disease. Adjuvant chemotherapy plus radiotherapy is rec-

ommended for patients with thymic carcinoma with either grossly (R2)

or microscopically (R1) positive surgical margins. Clinical surveillance is

recommended only for patients with no evidence of capsular invasion,

and adjuvant radiotherapy alone is recommended for those with capsular

invasion after complete surgical resection (R0). Recommendations are

similar for patients with thymoma after R0 and R2 resections, except

that adjuvant radiotherapy alone is usually used after R1 resection. Fur-

ther surgical resection and adjuvant chemotherapy alone are not generally

indicated for thymic tumors.

Answer 19.8. The answer is C.

This young man presents with symptoms of superior vena cava syndrome

caused by a locally advanced, primarily unresectable thymic carcinoma.

Symptoms caused by compression or invasion of mediastinal structures,

including anterior chest pain, cough, dyspnea, and superior vena cava syn-

drome, occur in up to 70% of patients with thymic carcinoma, whereas

paraneoplastic syndromes are rare. Because completeness of resection is

one of the most important predictors of outcome, multimodality therapy

should be recommended for all patients with thymic neoplasms, both thy-

moma and thymic carcinoma, whose tumors are judged to be primarily

unresectable because of the extent of local invasion. The most commonly

studied approach includes neoadjuvant cisplatin-based chemotherapy fol-

lowed by surgical resection and postoperative radiotherapy. Cumula-

tive results reveal that neoadjuvant chemotherapy results in an objective

response rate of 89% and a complete response rate of 31%. These studies

included patients with both thymoma and thymic carcinoma. Long-term

survival remains the goal of therapy for patients with locally advanced

disease, with one trial noting a 7-year disease-free survival rate of 83%

after trimodality therapy. Therefore, purely palliative approaches are only