Warning: This information is provided for information purposes. You should always discuss your individual case with your own physician. Keep in mind that there are different stages of DSRCT tumors, from one local tumor to metastatic disease. Please find out which stage your physician considers your tumor to be.
Introduction
- The following are the tools used by the medical field to diagnose or keep an eye on DSRCT tumors (well, all types of cancer). Please be aware that in stage IV disease some of these diagnostic tools do not pick up the extent of cancer that can be present within the abdomen. This information is based on numerous reports from patients with DSRCT who have had an abdominal CT or PET scan and than during surgery it is discovered there is widespred disease. This is possibly due to the fact that DSRCT seems to come in a variety of sizes from volley ball sized abdominal tumors to golf ball size to nodules to microscopic seeding.
- Patients should be aware that CT and PET scan reports of 'no visible evidence' of disease can mean that the diagnostic tools can't spot the cancer because it is too small. The only way to determine if a patient has no disease is from biopsy or exploratory surgery or from the passage of time (nothing shows up). They needed to have a few consecutive CT scans with 3 month in between to see if more lung meets are getting seen. One of the reasons for this type of delay is that sarcomas (like DSRCT) are often already disseminated when the primary is respected and microscopic disease can stay dormant for an uncertain period of time, thus there is no way to know the real number. Treatment will depend on the location and the number of the mets and how agressive are they, so they need to wait for the next scan to find it out.
- It is hoped that this information will help patients establish a dialogue with their physicians as they try to determine the best course of treatment.
Biopsy
Sarcoma tumors are rare. Desmoplastic small round cell tumors are even rarer. Because of this a biopsy from a suspected sarcoma should be reviewed by a sarcoma pathology specialist.
It is critical before treatment begins to know exactly which type of sarcoma you have.
There are two types of biopsies that can be done, either a needle biopsy in the doctors office or incisional biopsy in the hospital. In the majority of DSRCT cases the biopsy is done in the operating room. A small incision will be made and a sample of tissue removed.
With DSRCT diagnosis has been known to take up to a week or more. It is important to get a correct diagnosis as quickly as possible. Sometimes DSRCT can be mistaken for Rhabdomyosarcoma, Germ Cell tumor, or Uterine sarcoma. Because DSRCT is rare the biopsy may need a second or third opinion.
X-Ray
Helpful for the initial test to spot tumors. Usually a patient will have an x-ray first before being recommended for a PET, CT, or MRI.
Chest x-rays are also used for spotting metastatic cancer in the lungs.
Computed Tomography (CT)
Computed tomography (CT)is often used to locate tumors which are in the abdomen, pelvis, or chest. In the case of DSRCT it should be noted that the scans can pick up large tumors, but often misses smaller nodules and will not pick up the extent of microscopic disease.
Your oncologist will probably order a 'baseline' CT to be used as your treatment begins. The baseline CT will be compared to future CT to see if there is any change in your tumors as you undergo chemotherapy or radiation.
The CT is a useful tool for the oncologist to keep track of disease progress. Oncologists will use a CT to see if the chemotherapy or radiation treatments are reducing the size and amount of disease. When the tumors reach a certain size than the oncologist will often recommend surgery to remove the bulk of the tumors. If the CT reveals that the tumors are progressing, than the oncologist will determine that the chemotherapy is not working and will try to change the protocol.
CT can also be used in conjunction with a PET scan to give the oncologist even more information about the location and size of tumors.
Positron Emission Tomography (PET)
Positron emission tomograpy (PET) produces a three dimensional image or map of functional processes in the body. This machine is used in Nuclear Medicine and works for cancer by looking at the metabolic activity of cells in the body. Malignant tumor cells have an active metabolism and therefore can be seen on a PET scan.
In the case of DSRCT, if there are any active cancer cells than the image will 'light' up as spots.
An oncologist will order a PET scan to use as a baseline and compare the image with future PET scans. Sometimes a PET scan will be used in conjunction with a CT to give the oncologists more information about the disease.
Magnetic Resonance Imaging(MRI
In general this tool is useful to image tumors in the extemeties. It gives the oncologist a detailed view of the tumor and the surrounding organs and structures within the body.
Exploratory Surgery
This type of surgery is undertaken to observe the tumor or tumor location. A biopsy may be taken at this time.
Exploratory surgery and biopsy may be the only reliable way to tell if there is any more visible disease present. Patients should remember that no visible evidence of disease does not account for microscopic or disease too small to see.
Possible Markers
Desmoplastic small round cell tumor is a unique, chimeric disease that shares common genetic features with Ewings Sarcoma and Wilms tumor. This distinguishing feature helps in the final diagnosis of the disease.
At the moment there is no known 'marker' for DSRCT that would alert a patient that the disease is live and present.
Chemosensitivity Testing
There are some labs that offer the service of testing a patients tumor sample to see which chemicals the tumor will respond to. Patients are encouraged to discuss this issue with their oncologists to see if there is any benefit to the test.
Patients should use this type of testing as a tool and not as a final decision on which chemo drugs to use. There are many factors to consider, including the fact that some DSRCT tumors may respond differently within the body. Also, patients should be aware that the test may not always be reliable. Much depends upon how much tumor sample is used, the weight or amount of chemicals tested on the tumor, the drug combinations tested. Also once the patient has undergone chemotherapy and wishes to have the tumor retested, new samples will need to be retreived. The second testing may than conflict with the first test.
The benefit of chemosensitivity testing for soft tissue sarcoma remains controversial. There have been recent studies to indicate the value in individual testing. WJSO:Feasibility of chemosensitivity testing in soft tissue sarcomas
Facilities that offer Chemosensitivity Testing for soft tissue sarcoma:
- Oncotech
- 15501 Red Hill Avenue
- Tustin, CA 92780
- Phone: (800) 576-6326
- Fax: (714) 566-0421
- Client Services
- Phone: (800) 662-6832
- Fax: (714) 566-0423
- [Rational Therapeutics, Inc
- 750 East 29th Street
- Long Beach, Ca. 90806
- Patient Relations Department: 562-989-6455, ext. 104
DSRCT References
Contact: dsrct.wiki@gmail.com