Friday, June 6, 2008

What’s New in Cancer Research?

Why do there seem to be so many

I just got back a couple of days ago from Chicago, where I attended the annual meeting of the American Society of Clinical Oncology (ASCO). This is an enormous meeting, attracting over 30,000 participants from across the country and around the world. All of the specialties involved in cancer care are represented – surgeons, medical oncologists, pediatric oncologists, radiation oncologists, social workers, psychiatrists, orthopedists, and others.

The annual meeting is an opportunity for researchers from around the world to present their findings to each other. I thought it might be interesting to discuss some of the interesting presentations about sarcomas that I saw:

Better Treatment for Ewing’s Sarcoma
One of the most exciting talks at the meeting (at least, for me) was Dr. Womer’s presentation of the results of the last Children’s Oncology Group clinical trial for patients with localized Ewing’s sarcoma. In this study, patients were randomly assigned to receive the same chemotherapy (cycles of vincristine/doxorubicin/cyclophosphamide alternating with cycles of ifosfamide/etoposide) every 3 weeks or every 2 weeks. The question was whether chemotherapy works better given closer together (time intensive), or whether there would be too many side effects. Well, the results are in, and time intensive chemotherapy works! The patients who received the chemotherapy every 2 weeks had a 78% 4-year event-free survival rate, compared with 70% for the patients treated at the standard 3 week interval. Although this improvement was limited to patients younger than 18 years old, this is probably because there were too few older patients to evaluate.

Photo Credit


The Genetics of Rhabdomyosarcoma
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of children and adolescents. There are several different types of RMS based on microscopic appearance, but the two most common types are called “alveolar” and “embryonal.” These types refer to the microscopic appearance of the tumors (alveolar because the tumor resembles the alveoli, or airspaces, of the lungs; embryonal because the tumor looks like very immature muscle cells). It has long been known that alveolar RMS is characterized by chromosomal translocations (where a piece of one chromosome is “swapped” for a piece of another one), but embryonal RMS is not. Dr. Barr presented data showing that embryonal RMS are characterized by specific changes in chromosome 11 instead.

Interestingly, not all alveolar RMS has these chromosomal translocations, and 63% of those that do not, instead have the same chromosome 11 changes seen in embryonal RMS. A detailed genetic analysis also showed that by this test, so-called “translocation negative” alveolar RMS appears to be more similar to embryonal RMS than to “translocation positive” tumors. This raises the possibility that, in the future, we may do away with tumor descriptions based on microscopic appearance in exchange for genetic descriptions that probably more closely reflect the underlying causes and behavior of the tumors.

Alveolar Rhabdomyosarcoma
Photo Credit


Synovial Sarcoma
One of the more rare types of sarcoma we treat is called synovial sarcoma. Doctors from the Rizzoli Institute in Italy looked back over the records of 250 synovial sarcoma patients treated there since the 1970’s to try to learn more about this rare disease. They presented some very important findings: 1) radiation therapy improves survival in patients with localized disease, but chemotherapy did not; 2) some patients relapse very late (more than 5 years from the end of treatment), suggesting that we need to follow these patients for a very long time; 3) patients who have a local relapse are often cured with further treatment, and it did not seem to matter whether this was a rapid relapse or a late relapse. This is an important study because it is the largest report on a single series of synovial sarcoma patients treated at a single institution.

Samarium to treat Osteosarcoma
Finally, I had the honor of presenting the results of my Phase I study of samarium-153 for the treatment of patients with osteosarcoma metastatic to bones. Samarium-153 is a radioactive agent that targets bone lesions. Because it was a Phase I study, the goal was to identify a dose of the drug we could give that would allow patients to recover safely and quickly from the side effects. Not only did we find what that dose is, but we also showed that this drug could be given to patients who had a LOT of previous treatment, and they had no more side effects than patients who had not been treated at all. Our next step will be to figure out how best to integrate this drug into treatment regimens based on chemotherapy, and hopefully one day this will be an important addition to our arsenal of therapies for osteosarcoma patients.

Unfortunately, my schedule did not allow me to make it to the presentation of the data regarding vitamin D and breast cancer, but you can read more about that study here.

Related Posts:
Vitamin D and Breast Cancer
Osteosarcoma Symposium in Houston
Children's Oncology Group Meeting
Medicine from the Sea

4 comments:

Anonymous said...

I lost my 4 year-old son, to fusion-negative, ARMS three years ago. I did not know that his tumor was fusion negative until I met with Dr. Barr about raising funds for his research. You know, to us, parents, we don't really care what you call it. We just know that our kids have a terrible cancer and that no one knows how to stop it. We just want to save our kids. I hope this finding will help in some way.
I can't help but be cynical - but great, you're gonna rename it according to a different set of criteria. Is that gonna bring my son back or save others?????

Doctor David said...

I'm so sorry that you lost your son to this horrid disease.

You are absolutely right, renaming the disease won't bring your son back. Our hope, though, is that new insights into the biology of RMS might, in fact, help other children in the future. As we learn more about the basic biology of these tumors, we should be able to develop treatments that work differently for different sarcoma diagnoses. Understanding more about the differences between fusion-positive and fusion negative alveolar RMS should one day lead to better treatments. It is that hope, along with our shared anger at this terrible cancer, that drives us to keep trying to do a better job treating children like your son, so that one day no one will have to face what you went through.

μονάδa εξωσωματικής γονιμοποίησης said...

Hi

Everyone knows about cancer.Cancer is a very dangerous deciease in past and whose are effective in the case of cancer people says he is to near death.

But now many doctor and scientist are research of cancer.They are successful in this research.Now cancer is not a special dicease, it is a normal dicease,"just like temprature.

Anonymous said...

My 5 year old son, Arthur BALCAR-SMITH is fighting Fusion Negative RMS for the third time in 5 years.

He is 8 months into his third year-long COG trial / protocol and in otherwise perfect health like his siblings.

After 5 year, I have never received a questionaire or a blood test and any observation(ie; two children with RMS in a public school of 350 children)is ignored along with any question of cause (ie; Grandfather 40 years Chemical Engineer).

We have banked his tumours with COG for future research. However, no one appear interested in anything other than discussing new RMS classifications, altering definitions and generating lower and lower standards of published papers and research on RMS appear to involve a race between rival lab's as to who can poison or xeno-graft the most rats.

This is not a personal attack, Arthur lost his last "RMS4" Relapse friend this week.

Stuart