Second tumor: No increased risk after brachytherapy
Many men are afraid of developing a malignant tumour again after successful prostate cancer treatment. Radiotherapy in particular is suspected of promoting the development of intestinal and bladder cancer. "But thanks to the most modern radiation therapy methods, such as internal radiation by means of brachytherapy, it is now possible to optimally protect healthy tissue from radiation damage," explains Dr. Stephan Neubauer, urologist at the West German Prostate Center in Cologne.
No higher risk 5 and 10 years after treatment
Proof of this is provided by a large comparative study of more than 6400 men by the British Columbia Cancer Agency (1). The Canadian scientists were able to show that patients with a localized prostate carcinoma who had undergone a special form of brachytherapy, the so-called seed implantation, had no higher risk of developing a second tumor five or ten years after treatment than men whose prostate had been removed in an operation. This applied not only to secondary malignancies outside the pelvis, such as lung cancer, but also to tumours of the bladder and rectum. According to the authors of the study, whether a second tumour occurs after prostate cancer treatment depends more on whether the patient was a smoker or already at an advanced age.
A US study (2) involving 2120 patients also showed that men undergoing brachytherapy do not have to fear a higher risk of developing a second tumour. This applies to both seed implantation and HDR afterloading combined with external radiation.
Precise irradiation spares other organs
"State-of-the-art computer technology and the use of imaging techniques enable us to detect the target area with millimeter precision and to irradiate the prostate with pinpoint accuracy," says Dr. Neubauer. For example, in contrast to external radiation, brachytherapy involves the introduction of tiny radiation sources (seeds) directly into the tumor. The seeds remain there for several months and deliver high-dose radiation specifically to the tumour tissue. "This has the advantage that the tumour is destroyed without damaging surrounding healthy tissue such as the bladder, colon or sphincter," says the Cologne urologist.
Aftercare is the be-all and end-all
Nevertheless, it is important to also look for secondary tumors in the follow-up examinations," emphasizes Dr. Neubauer. Bladder and rectum should therefore be examined at regular intervals. This has less to do with radiation or surgery, but rather with the possibly higher tendency (disposition) of patients to develop cancer, says the Cologne-based specialist.
(1) Hamilton SN et al: Incidence of second malignancies in prostate cancer patients treated with low-dose-rate brachytherapy and radical prostatectomy. Int J Radiat Oncol Biol Phys.2014 Nov 15;90(4):934-41. doi: 10,1016/j.ijrobp.2014.07,032. Epub 2014 Sep 17.
(2) Huang J, Kestin LL, Wallace M et al: Analysis of second malignancies after modern radiotherapy versus prostatectomy for localized prostate cancer. Radiother Oncol 2011 Jan;98(1):81-6. doi: 10.1016/j.radonc.2010.09.012. Epub 2010 Oct 14.