Early mesothelioma revisited

Abstract

Very recently, a randomized controlled trial successfully proved a significant reduction in lung cancer mortality with CT screening [1]. This was an epoch-making report. Although intuition had been telling us that early detection of lung cancer converts directly into reduced mortality, most previous studies have only proven an improved detection rate; they have failed to show any reduction of mortality from lung cancer [2–4]. The success of the present study was obtained by focusing on a high-risk population. Although primary lung cancer had been—as MPM still is—considered a highly incurable disease, its mortality is currently much improved. For example, in the Japanese Lung Cancer Registry, the 5-year survival rate for all surgical cases was 51.9% in 1996 and 69.6% in 2004 [5]. This striking improvement in survival may be multifactorial, but early diagnosis and early treatment are undoubtedly the most important factors. In this registry, 48.1% of the 11663 surgical cases in 2004 were at pathological stage Ia, and the 5-year survival rate of this subgroup reached 85.1% [5]. On the other hand, MPM remains one of the most incurable malignancies, and its median survival time (MST) after diagnosis is approximately 1 year [6–8]. Therapy for MPM (just like other malignancies) has evolved considerably, and is still evolving: adjuvant chemotherapy [9], neoadjuvant chemotherapy [10], the introduction of pemetrexed [11–13], the reduction in mortality/ morbidity after extrapleural pneumonectomy (EPP) [14, 15], the introduction of radical pleurectomy/decortication (P/D) [16–19], adjuvant radiotherapy [20, 21], the introduction of intensity-modulated radiotherapy (IMRT) [22–25], and so on. Trimodality treatment (TMT) with induction chemotherapy followed by extrapleural pneumonectomy (EPP) and postoperative radiation was introduced as an integration of the above developments, and is currently considered the most powerful therapeutic option [10, 26–32]. TMT is only feasible for highly selected patients with early MPM and excellent cardiopulmonary reserve. However, notwithstanding its high cost, its extremely high risk, and its severe deterioration of cardiopulmonary function, MST after TMT still does not reach 20 months in most large studies [29–31, 33], so some researchers are skeptical about aggressive surgery in MPM patients [33, 34]. In the above context, the current therapeutic options are not sufficient to provide acceptable survival in cases with non-early MPM.