An anonymous reader writes "BBC news is reporting a new handheld scanner that can detect cancers in patients. In clinical trials at a hospital in Milan, the scanner was able to correctly identify 93% of prostate cancer patients whose condition was later confirmed by a biopsy operation."
What about false positives?
by
DustMagnet
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· Score: 4, Insightful
93% sounds great. Even the 66% for breast cancer is amazing. What the article doesn't mention is false positives. I could identify 100% of all cancers if you let me have unlimited false positives.
-- 'SBEMAIL!' is better than a goat!!
Re:What about false positives?
by
DustMagnet
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· Score: 4, Informative
The article in New Scientist has some more details, but still no information on false positives.
-- 'SBEMAIL!' is better than a goat!!
Re:What about false positives?
by
Sgt+York
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· Score: 4, Informative
I wonder what the success rate of biopsy diagnosis is...
Biopsy is nearly 100% effective; the false positive/negative risks are low in the hands & eyes of a good pathologist. The hard part is knowing what to biopsy. Some other test has to be done beforehand to show you where the putative cancer is.
Even tumors ID'd with this device would need to be confirmed via biopsy, MRI or CAT scan. Most likely MRI followed by biopsy.
As for publication, they may not have submitted it yet (need more data, timid researchers), or reviewers haven't finished their reviews yet, or the editor is sitting on it to publish it alongside another paper, or the BBC could be blowing the data out of porportion (the latter is the most likely. Happens all the time.)
--
There is a reason for everything. Sometimes that reason just sucks.
Biopsy still necessary in many cases
by
Metameme
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· Score: 4, Insightful
IANAD, but my wife's currently on her third bout with lymphoma (NHL once, Hodgkin's twice) so I have researched this pretty heavily.
Biopsied tissue is not subjected to a pass/fail test for cancer. Often the excised tissue is tested against different combinations of chemotherapy drugs to see which the tumor(s) will respond to best. In addition, a biopsy can help determine what specific type of cancer cells are present; knowing that a patient has lymphoma says very little about rate of growth, type of treatment indicated, etc. There are several types of lymphomas, both Hodgkin's and non-Hodgkins. Even knowing the difference between those two categories is helpful as non-Hodgkin's can be treated with monoclonal antibodies whereas Hodgkin's cannot.
This device, if it lives up to the hype, can still help.
First of all, we've had a lot of failed biopsies because they took tissue from areas that were benign and had to go back for more tissue in different areas. If the device could determine *where* the cancer is, it would make a biopsy more effective the first time around and prevent a lot of needless suffering and expense.
Secondly, many patients go through a staging surgery to determine the progression of the disease after the initial diagnosis. In lymphomas, the stages are ranked as I-IV, with an additional A or B tag. Simply knowing the cancer is both above and below the diaphragm in multiple sites will tell you that the patient is stage IV. The A/B tags represent whether there is organ involvement (B) or none (A).
Additionally, remission is often diagnosed through the results of CT and PET scans, which are not entirely conclusive but much less traumatic than surgery for additional biopsies, especially considering the effects of chemotherapy on the immune system and the healing ability of the body.
Hope this helps clear it up; anyone in the know please correct me if I'm wrong on any of this...
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93% sounds great. Even the 66% for breast cancer is amazing. What the article doesn't mention is false positives. I could identify 100% of all cancers if you let me have unlimited false positives.
'SBEMAIL!' is better than a goat!!
IANAD, but my wife's currently on her third bout with lymphoma (NHL once, Hodgkin's twice) so I have researched this pretty heavily.
Biopsied tissue is not subjected to a pass/fail test for cancer. Often the excised tissue is tested against different combinations of chemotherapy drugs to see which the tumor(s) will respond to best. In addition, a biopsy can help determine what specific type of cancer cells are present; knowing that a patient has lymphoma says very little about rate of growth, type of treatment indicated, etc. There are several types of lymphomas, both Hodgkin's and non-Hodgkins. Even knowing the difference between those two categories is helpful as non-Hodgkin's can be treated with monoclonal antibodies whereas Hodgkin's cannot.
This device, if it lives up to the hype, can still help.
First of all, we've had a lot of failed biopsies because they took tissue from areas that were benign and had to go back for more tissue in different areas. If the device could determine *where* the cancer is, it would make a biopsy more effective the first time around and prevent a lot of needless suffering and expense.
Secondly, many patients go through a staging surgery to determine the progression of the disease after the initial diagnosis. In lymphomas, the stages are ranked as I-IV, with an additional A or B tag. Simply knowing the cancer is both above and below the diaphragm in multiple sites will tell you that the patient is stage IV. The A/B tags represent whether there is organ involvement (B) or none (A).
Additionally, remission is often diagnosed through the results of CT and PET scans, which are not entirely conclusive but much less traumatic than surgery for additional biopsies, especially considering the effects of chemotherapy on the immune system and the healing ability of the body.
Hope this helps clear it up; anyone in the know please correct me if I'm wrong on any of this...