This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Save to my personal folders Download to citation manager Rights & Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ferrari, A. Articles by Casanova, M. Search for Related Content PubMed PubMed Citation Articles by Ferrari, A. Articles by Casanova, M. Social Bookmarking                            What's this?

Specification on the Definition of Adult-Type Soft Tissue Sarcoma

Pediatric Oncology Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano, Italy

To the Editor:

We have followed with interest the debate¹ on the terms adult-type soft tissue sarcomas and nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) aroused by the definition we coined² and the subsequent editorial by Baker.³ Since we are responsible for this definition, we need to provide a brief specification to avoid any misunderstandings. Of course, we are sure that Baker intended no offense when he said that he did not like the term nonrhabdomyosarcoma (though similar terms, for example, non-Hodgkin's lymphoma are in widespread use), but it may be that this term reflects the fact that these tumors have often been treated in the past according to the principles adopted for rhabdomyosarcoma, which is a clearly distinct entity. But times are changing and both the Children's Oncology Group and the European Pediatric Soft Tissue Sarcoma Study Group are developing clinical trials specifically tailored for NRSTS.⁴ When we established our definition of adult-type soft tissue sarcomas—definitely malignant tumors, typical of adulthood, with morphological features resembling differentiated/mature tissues—we wanted to identify a more homogeneous subset of histotypes within the large heterogeneous group of NRSTS—excluding from a common analysis, for instance, borderline tumors, infantile histotypes, and small round cell tumors (which are biologically and clinically different entities that are sometimes studied together, giving rise to misleading results). In other words, to our mind, adult-type soft tissue sarcomas are a subgroup of NRSTS.

This is not just a matter of terminology, however. We do not believe that the different rates of occurrence of the various soft tissue sarcoma histotypes in different age groups can be used to hypothesize biologic differences,¹ because these data clearly reflect only the epidemiological incidence of the different histotypes (ie, the incidence peaks at around 20 to 30 years of age for synovial sarcomas, but around 50 years of age for liposarcoma). For the time being, we feel we have no reason to suggest any biologic differences between soft part sarcomas arising at different ages.

Actually, we are personally convinced that the definition of adult-type soft tissue sarcomas—though useful today—will only be suitable for the next few years, because we hope, in the near future, to have new molecular therapies targeted for each histotype (ie, imitinib for dermatofibrosarcoma protuberans and ET-743 for myxoid liposarcoma, but also taxanes for angiosarcoma). We will need to study soft tissue sarcomas no longer as a whole group, but concentrating separately on each histotype. This is only feasible if there is close cooperation between international groups, and between pediatric and medical oncology groups, as Baker said.³ But this is not as easy as it may seem. The present debate (the "quip" from Baker³ and the prompt and rather resentful letter from Spunt and Pappo¹) conceals the enormous distance between the two worlds of pediatric oncology and adult medical oncology, each inclined to defend its own background and its own strategy. Why it is so arduous to get pediatric oncologists and medical oncologists (concerned with similar diseases) to collaborate is hard to say. Until not long ago at least, a 15-year-old with synovial sarcoma was treated differently from a 22-year-old with the same tumor, even within the same experienced institution.⁵ We think that the people who pay the highest price for this situation are the adolescent and young adult patients, an age group in which the lack of progress in improving survival has been clearly associated with the lack of these patients' enrollment in clinical trials, particularly for patients with sarcomas.⁶ In conclusion, we are convinced that using a correct, generally accepted terminology is important, but it is becoming more and more important to focus on overcoming the obstacles preventing a fruitful cooperation between pediatric and medical oncologists.

Authors' Disclosures of Potential Conflicts of Interest

The authors indicated no potential conflicts of interest.

REFERENCES

1. Spunt SL, Pappo AS: Childhood nonrhabdomyosarcoma soft tissue sarcomas are not adult-type tumors. J Clin Oncol 24:1958-1959, 2006[Free Full Text]

2. Ferrari A, Casanova M, Meazza C, et al: Adult-type soft tissue sarcomas in pediatric age: Experience at the Istituto Nazionale Tumori in Milan. J Clin Oncol 23:4021-4030, 2005[Abstract/Free Full Text]

3. Baker LH: Medical and pediatric oncology, not adult and pediatric oncology. J Clin Oncol 23:4003-4005, 2005[Free Full Text]

4. Ferrari A, Casanova M: New concepts for the treatment of pediatric nonrhabdomyosarcoma soft tissue sarcomas. Expert Rev Anticancer Ther 2:307-318, 2005[CrossRef]

5. Ferrari A, Gronchi A, Casanova M, et al: Synovial sarcoma: A retrospective analysis of 271 patients of all ages treated at a single institution. Cancer 101:627-634, 2004[CrossRef][Medline]

6. Bleyer A, Montello M, Budd T, et al: National survival trends of young adults with sarcoma: Lack of progress is associated with lack of clinical trial participation. Cancer 103:1891-1897, 2005[CrossRef][Medline]

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Save to my personal folders Download to citation manager Rights & Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ferrari, A. Articles by Casanova, M. Search for Related Content PubMed PubMed Citation Articles by Ferrari, A. Articles by Casanova, M. Social Bookmarking                            What's this?