Are there - or should there be - pediatric sarcoma centers?

by

Joan Darling, Ph.D.

Environmental Consultant

Lincoln, Nebraska.

[Editor's Note: Joan is a biologist. She is also mother of two, one of whom is an eight-year survivor of alveolar rhabdomyosarcoma. Joan spends much of her spare time as Co-list manager of the ACOR Rhabdo-Kids mailing list and as a Patient Advocate for the Children's Oncology Group.] 

This article had its genesis in a discussion on an on-line sarcoma support group.  Adult sarcoma patients often suggest to new group members that they seek out sarcoma centers, institutions with teams of sarcoma specialists. This recommendation is echoed in “A Roadmap for Sarcoma Research”, a report of the National Cancer Institute’s Sarcoma Progress Review Group (click here). The rationale is the rarity of sarcoma, which comprises less than one percent of adult cancers. Thus, an oncologist who is not at a sarcoma center might see only a handful of sarcoma patients during a career, and is unlikely to be familiar with the latest diagnostic and treatment methods. In contrast, sarcoma centers would have teams of medical oncologists, pathologists, surgeons, and radiation oncologists who had seen dozens or even hundreds of sarcoma patients.  

The question was asked on-line as to whether pediatric sarcoma centers exist as well, and if they do whether children with sarcomas should be treated at those centers. I gave my opinion, which is that to the best of my knowledge, there are no pediatric sarcoma centers in the same sense that there are adult centers.  But I do not see that as a problem.  Most pediatric sarcoma patients will get appropriate treatment at many institutions, for reasons given below.

Current State of Pediatric Sarcoma Treatment

Although childhood cancer fortunately is a relatively rare disease with about 13,000 children in the U.S. diagnosed annually, sarcomas make up a much higher percentage than in adults. Sarcomas account for about 15 percent of pediatric cancers. Thus the average pediatric oncologist is likely to see a couple of sarcomas each year, instead of a couple of sarcomas in a career. 

In addition, almost all pediatric oncologists are associated with pediatric hospitals. These hospitals are tertiary care facilities that provide a specialized team of health care providers with the skills to image, sedate, draw blood, administer chemotherapy, and operate on children.

Perhaps most importantly, pediatric oncology clinics are centers of research. Most pediatric hospitals in the U.S. and Canada are members of the Children’s Oncology Group (COG), the cooperative group that designs and implements clinical trials for pediatric cancers.  Membership in COG guarantees that the institution has met group requirements for expertise in treatment of childhood cancer.  A newly-diagnosed child being treated at any of over 240 member institutions will have access to the same treatment protocols, whether or not her pediatric oncologist is a pediatric sarcoma specialist. 

Children’s hospitals in other countries also frequently are members of COG or other cooperative groups with similar research goals.  Membership in a cooperative group fosters a collegial atmosphere in which pediatric oncologists know and consult with one another.  For example, my daughter’s primary pediatric oncologist is a lymphoma expert, but we consulted with many sarcoma specialists during the course of her treatment.

The close intertwining of research and treatment means that most children with cancer are enrolled on clinical trials.  This produces a high level of standardized care.  Central pathology review is required for enrollment on COG sarcoma clinical trials, so a mistake in diagnosis is corrected before or soon after the start of treatment.  Patients are closely monitored for treatment success and side effects, which helps improve outcome.  And the treating physician must contact the study chair (a sarcoma specialist) if there are any questions or if treatment deviates from protocol.  Therefore, sarcoma experts are involved in the treatment of many children on these clinical trials, even if they are at a distant facility.

The nature of childhood cancer makes it unlikely that most families would travel to a sarcoma center, even if they existed. Childhood cancer means serious disruption to family routine and finances, and most families choose to have their children treated at the nearest pediatric oncology facility. Consequently, newly-diagnosed pediatric sarcoma patients typically are scattered among many hospitals.

Does that mean that every hospital is the same?  Absolutely not.  But I would always recommend finding the right doctor rather than a sarcoma center for children with sarcomas.  For example, surgery is an important part of sarcoma treatment, and although one surgeon deems a tumor inoperable, another with different expertise might successfully remove it.  Similarly, the experience of radiation oncologists and the type of equipment may vary from one hospital to another.  A family might opt to travel to a hospital that has a newer generation of radiation equipment capable of reducing damage to healthy tissues, such as IMRT or proton beam.  Some institutions run their own clinical trials, so the family of a child who has an unusual sarcoma or who has relapsed might search out a specialist.  But for most childhood sarcomas, almost any pediatric oncology clinic can provide the same front-line chemotherapy treatment.  If the family likes and trusts the pediatric oncologist, specialty doesn’t matter that much.

As a result of a generation of research, standard treatments have been developed that have good success for some of the more common childhood sarcomas. I know the most about rhabdomyosarcoma (RMS), the cancer my daughter had. Overall, about 70 percent of children with RMS are considered to be “cured”, up from about 25 percent 30 years ago. But this rate varies greatly by stage and tumor site.  Stage 1 orbital RMS has close to 100 percent cure rate, while Stage 4 (metastatic) RMS as a terrible outcome of about 20 percent survival at 5 years. 

Gaps in Research

There are other problems besides the abysmal results for metastatic children.  In the December 2004 ESUN newsletter, Dr. Karen Albritton described the lack of progress that has been made in improving survival for adolescent and young adult (AYA) cancer patients, or the “teen gap”.  While survival rates for younger and older patients have increased at the rate of 1.5 percent per year over the last 20 years, there has been no increase in survival rates for AYA patients. As Dr. Albritton points out, these patients fall between the territories of the pediatric and adult oncologists.  Pediatric oncologists and their adult counterparts belong to different professional societies, attend different conferences, often practice at different hospitals.  Therefore, the opportunity for collaboration has been sharply limited, resulting in very little research focused on this age group.

As an example of the lack of collaboration, the National Cancer Institute has sponsored a series of State of the Science symposia on different cancers, and in 2002 a symposium was held on sarcoma. This would have been an ideal opportunity to encourage more interaction between adult and pediatric oncologists, as the SOTS leukemia meetings have done.  But only a handful of COG members were invited to attend, and most of the big names in pediatric sarcoma research and treatment were missing. 

The lack of collaboration is reinforced by another gap, that between sarcomas that typically occur in adults and those that typically occur in children (see Dr. Brennan’s Viewpoint in August 2004 ESUN). For example, leiomyosarcoma—the smooth muscle sarcoma—is an "adult" sarcoma, while rhabdomyosarcoma—the skeletal muscle sarcoma—is a "pediatric" sarcoma. The same doctors will not know both tumors equally well, contributing to the difficulty that children with LMS or adults with RMS sometimes have in finding the right doctors and treatments.

These two gaps—teen and tumor—have conspired to produce very few clinical trials designed for all patients with a particular type of sarcoma. For example, most adult clinical trials have a minimum age of 18, while pediatric oncology clinical trials until recently were limited to patients under the age of 21. The age limits in general make sense, as children are not just small adults.  There are strict rules about research on children, and there are medical, physical and emotional needs of ill children and their families that children’s hospitals may be uniquely qualified to fulfill.  But the good reasons also deny patients access to some treatments, based on age alone.

Within the last few years, the gaps have begun to close.  COG clinical trials for sarcomas now are open to patients up to age 50, and for the first time adults in their 20s, 30s, and 40s are being enrolled in the same clinical trials as children.  Similarly pediatric and adult cooperative groups are beginning to jointly sponsor clinical trials for synovial sarcoma, MPNST, and other “adult” sarcomas that also occur in children, as Dr. Albritton mentioned in her article. 

What about the Future?

In my opinion, it is crucial to close the teen and tumor gaps if sarcoma treatment is to progress as quickly as possible for all patients, not just for the underserved AYA patients.  Children make up about 20 percent of all sarcoma patients, and thus are a sizeable portion of the sarcoma community.  Because of the relatively large number of sarcomas in children and the relatively small number in adults, and because children get adult sarcomas and adults get pediatric sarcomas, closing the gaps results in a larger patient population for clinical trials of new treatments.  And more patients can result in more trials and faster trial results.

Closing the gaps also produces a larger and more attractive subject for research. I have no doubt that the next generation of cancer treatment will be targeted drugs like imatinib mesylate (gleevec) designed to attack the particular genetic mistakes that cause a normal cell to become cancerous. The long-promised “magic bullet” that homes in on the unique metabolism of cancer cells while sparing healthy cells will become a reality, but each bullet will be designed for one cancer.

In a perfect world, sarcomas should be among the first cancers for which targeted drugs are developed, as many of them have known genetic mistakes, often a single chromosomal translocation. Unfortunately, the world is not perfect.  It takes a boatload of research to get from the translocation unique to Ewing’s sarcoma to a targeted treatment. Sarcomas are rare and diverse, two characteristics that make it unlikely that pharmaceutical companies will spend their resources on this category of cancer.  It falls to government and private funding to make sure that researchers are not ignoring sarcomas in their quest for magic bullets. 

Our voices must be heard to keep that funding coming. If pediatric and adult sarcoma voices are united, our message will be stronger still.  And when effective targeted drugs have been developed, maybe all sarcoma patients will be able get appropriate treatment everywhere and we will no longer need to urge anyone to seek out sarcoma centers. 

V2N1 ESUN Copyright © 2005 Liddy Shriver Sarcoma Initiative