Chemo doesn't give permanent cure

Interesting article in today's Age :

http://www.theage.com.au/technology...ts-designed-to-kill-them-20150527-ghaul3.html

It describes an extensive survey by the Peter MacCallum Cancer Centre of ovarian cancer patients. Unfortunately, the long term prognosis for patients is not good. The survey showed that for the most common form of ovarian cancer, accounting for 70% of ovarian cancers, chemotherapy provides a good initial treatment but then frequently the cancer returns and around 60% of women with ovarian cancer will die within five years.

The article describes how patients develop resistance to chemo within 18 months, by

- cancer cells repairing their own DNA that was damaged by chemo
- cancer cells developing the ability to 'pump away' chemo aimed at them
- cancer cells recruiting healthy cells to block chemo

I'm wondering if HC posters would have any understanding of whether these processes cause many other cancers to return after chemo. My aunt, a heavy smoker, developed lung cancer. She had one lung removed and then the cancer returned a few years later. (As an aside, if any HC people are still smoking, a great incentive to give up is to try to listen to someone dying of lung cancer - every breath is a huge effort and they have no spare air left in the lungs to  speak even at normal volume.)

So, if many chemo treatments don't provide certain long term cures, do the new oncolytic immunotherapies do a better job? The trial results so far seem to suggest that recurrence of cancer is reduced, but it may be a little too soon to arrive at conclusions.  There is, however,  a massive market for OI to assist chemo to provide a better solution or perhaps to provide the first line of treatment. If OI and Cavatak helps give a permanent cure then there's even more incentive to develop this range of treatments as soon as possible. Would be interested in any comments.

Bellas