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Growing teratoma syndrome
Editorial Comment Editorial Comment to Growing teratoma syndrome: Clinical and radiographic characteristics Growing teratoma syndrome (GTS) is a rare clinical entity that was first described by Logothetis et al. in 1982.1 It occurs in the setting of non-seminomatous germ cell tumors, and is defined as a metastatic tumor (retroperitoneal or otherwise) consisting of mature teratoma that is enlarging during or after systemic chemotherapy, in the setting of normal serum tumor markers.1,2 Complete surgical resection is the main treatment of teratomas, which are characteristically chemoresistant and radioresistant.3 The development of platinum-based chemotherapy regimens in the treatment of non-seminomatous germ cell tumors with long-term survival greater than 90% is a testament to the curability of most testicular tumors. Unfortunately, some patients will have continued growth of their metastatic sites even with normalization of serum tumor markers after chemotherapy, and this should make the treating clinician suspect the presence of GTS. Two hypotheses behind GTS development are that chemotherapy regimens either transform malignant cells into “benign” teratomatous elements, and/or chemotherapy regimens only destroy malignant cells, therefore leaving a chemoresistant teratoma behind.4 Although teratoma is described as histologically benign, these elements might grow to extreme sizes5 and compromise adjacent structures, and some might undergo malignant transformation. Novel oral therapies – such as cdk4/6 inhibitors – have been recently used in a small number of patients with GTS (reference 21 in manuscript), with some stabilization of disease noted, but no tumor regression, which is not surprising, as these drugs are mainly tumoristatic. The present study by Lee et al. describes the clinical, radiographic and surgical characteristics of GTS from two academic medical centers with expertise in the type of major surgery typically involved in the treatment of GTS.6 The small number of patients (n = 15) treated during this 7-year period attests to the rarity of this entity, which was similarly observed by Spiess et al. at 2.2% (9/408) over a 25-year period at another academic medical center.3 Even with the small number of patients in the current report, there are several notable and worthy observations that can be made. First, the discordant rates of teratoma between the resected metastatic specimen and the primary testicular tumor highlight the inability to predict GTS by simply assessing the percentage of teratoma in the primary tumor specimen. Second, there is no growth rate that specifically characterizes or defines GTS, or that correlates with patient outcomes after surgical resection. In a larger series with 30 patients
© 2014 The Japanese Urological Association
over a 12-year period, the 5-year overall survival was noted as 90%.2 Third, the surgical morbidity might be high, which is not surprising given the size and locally invasive nature of GTS, suggesting that earlier intervention with complete resection, preferably at a major center by an experienced urological surgeon, could result in improved outcomes. At present, we should aim to recognize GTS as early as possible by using the clinical clues previously described, and treat the appropriate patients with GTS using aggressive and complete surgical resection by expert urological surgeons. Despite the description of GTS more than 30 years ago,1 the rarity of this entity makes it difficult to prospectively study this disease with rigorous statistical methods. However, major medical centers with expertise in this disease should seek the opportunity and join forces – in a multicenter and multidisciplinary approach – to investigate and better understand this orphan disease on a molecular, pathological, radiological, surgical and therapeutic level. Dae Y Kim M.D., Ph.D. and Jose A Karam M.D. Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA [email protected] DOI: 10.1111/iju.12477
Conflict of interest None declared.
References 1 Logothetis CJ, Samuels ML, Trindade A, Johnson DE. The growing teratoma syndrome. Cancer 1982; 50: 1629–35. 2 Andre F, Fizazi K, Culine S et al. The growing teratoma syndrome: results of therapy and long-term follow-up of 33 patients. Eur. J. Cancer 2000; 36: 1389–94. 3 Spiess PE, Kassouf W, Brown GA et al. Surgical management of growing teratoma syndrome: the M. D. Anderson cancer center experience. J. Urol. 2007; 177: 1330–4; discussion 1334. 4 Gorbatiy V, Spiess PE, Pisters LL. The growing teratoma syndrome: current review of the literature. Indian J. Urol. 2009; 25: 186–9. 5 Karam JA, Raj GV. Growing teratoma syndrome. Urology 2009; 74: 783–4. 6 Lee DJ, Djaladat H, Tadros NN et al. Growing teratoma syndrome: clinical and radiographic characteristics. Int. J. Urol. 2014; 21: 905–8.
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Growing teratoma syndrome
Editorial Comment Editorial Comment to Growing teratoma syndrome: Clinical and radiographic characteristics Growing teratoma syndrome (GTS) is a rare clinical entity that was first described by Logothetis et al. in 1982.1 It occurs in the setting of non-seminomatous germ cell tumors, and is defined as a metastatic tumor (retroperitoneal or otherwise) consisting of mature teratoma that is enlarging during or after systemic chemotherapy, in the setting of normal serum tumor markers.1,2 Complete surgical resection is the main treatment of teratomas, which are characteristically chemoresistant and radioresistant.3 The development of platinum-based chemotherapy regimens in the treatment of non-seminomatous germ cell tumors with long-term survival greater than 90% is a testament to the curability of most testicular tumors. Unfortunately, some patients will have continued growth of their metastatic sites even with normalization of serum tumor markers after chemotherapy, and this should make the treating clinician suspect the presence of GTS. Two hypotheses behind GTS development are that chemotherapy regimens either transform malignant cells into “benign” teratomatous elements, and/or chemotherapy regimens only destroy malignant cells, therefore leaving a chemoresistant teratoma behind.4 Although teratoma is described as histologically benign, these elements might grow to extreme sizes5 and compromise adjacent structures, and some might undergo malignant transformation. Novel oral therapies – such as cdk4/6 inhibitors – have been recently used in a small number of patients with GTS (reference 21 in manuscript), with some stabilization of disease noted, but no tumor regression, which is not surprising, as these drugs are mainly tumoristatic. The present study by Lee et al. describes the clinical, radiographic and surgical characteristics of GTS from two academic medical centers with expertise in the type of major surgery typically involved in the treatment of GTS.6 The small number of patients (n = 15) treated during this 7-year period attests to the rarity of this entity, which was similarly observed by Spiess et al. at 2.2% (9/408) over a 25-year period at another academic medical center.3 Even with the small number of patients in the current report, there are several notable and worthy observations that can be made. First, the discordant rates of teratoma between the resected metastatic specimen and the primary testicular tumor highlight the inability to predict GTS by simply assessing the percentage of teratoma in the primary tumor specimen. Second, there is no growth rate that specifically characterizes or defines GTS, or that correlates with patient outcomes after surgical resection. In a larger series with 30 patients
© 2014 The Japanese Urological Association
over a 12-year period, the 5-year overall survival was noted as 90%.2 Third, the surgical morbidity might be high, which is not surprising given the size and locally invasive nature of GTS, suggesting that earlier intervention with complete resection, preferably at a major center by an experienced urological surgeon, could result in improved outcomes. At present, we should aim to recognize GTS as early as possible by using the clinical clues previously described, and treat the appropriate patients with GTS using aggressive and complete surgical resection by expert urological surgeons. Despite the description of GTS more than 30 years ago,1 the rarity of this entity makes it difficult to prospectively study this disease with rigorous statistical methods. However, major medical centers with expertise in this disease should seek the opportunity and join forces – in a multicenter and multidisciplinary approach – to investigate and better understand this orphan disease on a molecular, pathological, radiological, surgical and therapeutic level. Dae Y Kim M.D., Ph.D. and Jose A Karam M.D. Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA [email protected] DOI: 10.1111/iju.12477
Conflict of interest None declared.
References 1 Logothetis CJ, Samuels ML, Trindade A, Johnson DE. The growing teratoma syndrome. Cancer 1982; 50: 1629–35. 2 Andre F, Fizazi K, Culine S et al. The growing teratoma syndrome: results of therapy and long-term follow-up of 33 patients. Eur. J. Cancer 2000; 36: 1389–94. 3 Spiess PE, Kassouf W, Brown GA et al. Surgical management of growing teratoma syndrome: the M. D. Anderson cancer center experience. J. Urol. 2007; 177: 1330–4; discussion 1334. 4 Gorbatiy V, Spiess PE, Pisters LL. The growing teratoma syndrome: current review of the literature. Indian J. Urol. 2009; 25: 186–9. 5 Karam JA, Raj GV. Growing teratoma syndrome. Urology 2009; 74: 783–4. 6 Lee DJ, Djaladat H, Tadros NN et al. Growing teratoma syndrome: clinical and radiographic characteristics. Int. J. Urol. 2014; 21: 905–8.
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