Cancer Prevention, Detection, and Chemotherapy 6
As far as the cervical cancer screening recommendations, any woman having intercourse, initial smear normal, repeat once a year. First two smears normal, every three years to age 35 and every five years to 65. There’s some people that don’t agree with this. Low risk women over 65 with prior normal smears or in high risk such as with age, continue to do yearly.
One of my colleagues who is a gynecologic surgeon is very upset with this type of approach to how often you should do your pap smears. He says his problem is, “Okay, you can do this and you only do it every three or five years.” He says, “But that’s where all my cancers are and you can go out there and you’ll see a couple of my patients who are now dying of cervical cancer.” So he particularly feels you should do it continuously much more often. But these are the recommendations at the present time.
In Denmark, they were having a terrible time because they didn’t seem to be able to control this at all so they decided every woman is going to get a pap smear. As you can see, the incidence went up and then plummeted as the screening became effective and the mortality in these patients went up a little bit but then it was going steadily down again related to the fact that we’re doing adequate and good pap smears.
I had to put lung cancer screening in here as to effects on mortality rate and if they get a chest x-ray three times a year there’s no effect at all. If they have sputum cytology three times a year, there’s no effect at all. So in other words, our screening is of no value. It’s not effective in patients with lung cancer.
Prostate cancer is a bigger problem and you’re going to see more and more of that as time goes on. New cases now, 334,000, deaths 42,000. A significant problem that’s getting bigger all the time because we ignored a lot of people who said the screening for prostate cancer, PSA, is of no value and that’s obviously not true. It’s been proven now that it’s been a very significant improvement in our ability to pick up prostate cancer.
The PSA is a glycoprotein. It’s a serine protease lysosomal coagulation and it’s positive in 98% of prostate cancer. There’s very few things that are positive at such a high incidence and so you can see why this has been very helpful as we check on our patients.
PSA elevations are found in benign prostatic hypertrophy and inflammation and these can really cause a problem for the practicing physician. With inflammation, the PSA goes up to like 8 or 10, maybe even 20. Now you think the patient’s got the cancer and it’s actually only inflammation or BPH. So we have to be careful about that as time goes on.
Prostate cancer screening. First of all, you should be aware that the African American has a much higher incidence of these cancers than does the regular Caucasian and that goes through all these various groups. Digital rectal exam being age 50 and yearly. High risk groups, the African American age 40-45. Asymptomatic men, if the tumor is found more favorable with its stage. Digital rectal exam, DRE, less effective than PSA and I think we all know that.
Now when we’re talking about prostate cancer detection, same sort of problem as we saw in the polyposis deal and here you can see the initial screening 60 plus percent had detection of prostate and then as time went on, year 3, year 4 it went down further and further.
Adjuvant therapy of proven value with breast cancer in the premenopausal and postmenopausal and also Dukes’ C colon cancer.
The adjuvant chemotherapy of proven value in this group include Dukes’ C colon cancer treated with fluorouracil and levamisole and rectal cancers with radiation and fluorouracil.
New chemotherapy agents that you’ll be starting to work with with the oncologists include irinotecan. Cancer uses are fluorouracil resistant colon cancer. Side effect of note is diarrhea. Cladribine is used to treat hairy cell leukemia, beta cell lymphoma and is associated with fever and sepsis. Topotecan is relapsed ovarian cancer where it can be quite effective and it causes diarrhea and dyspnea in some cases.
Now we talk about new chemotherapy agents again, if we look at Taxol or paclitaxel, it works on the microtubules. Its cancer use is ovary, bladder, lung and breast. Side effects are myelosuppression, neurologic symptoms and fatigue. Vinorelbine or Navelbine, microtubule assembly. Lung, breast, myelosuppression and some neuropathy. Gemcitabine is one we’re quite excited about. It causes DNA inhibition but it’s active, although it’s not a lot, it’s definitely active in pancreas. It can cause fever and lethargy and myelosuppression.
I’ll just sum up to point out that gemcitabine, as I mentioned, doesn’t have a very high incidence of helping in these diseases. As you can see, the patients with response rate are usually in the rather low areas but nevertheless when you get a pancreas that goes two years, that’s pretty impressive.
Here’s another group which you can see ovary 22% response rate. Down here at pancreas 11%. But then they do last for a long time.
Non-small cell lung cancer. Paclitaxel and carboplatin are the best agents we feel. 62% objective response which is twice as high as it used to be and duration of response, it used to be about 20 weeks. Now it’s 53 weeks. So we’re doing better.
Here, again, we’re talking about treatment of resistant tumors and that works better with the use of these agents and this particular one is paclitaxel.
Cancer Prevention, Detection, and Chemotherapy at Cancer Treatment