He is one of a group of urology patients waiting too long for assessment or treatment. The Southern District Health Board confirmed this week it initiated an external review of the service earlier this year because of excessive patient delays. He said the urology department told him in March he would get a biopsy in "a month or two".
"I spoke to someone there today, and she said they’re still getting through people who have come in in December."
Mr Kerstens said health should be the top election issue as people were missing out on "basic fundamental healthcare".
Some of the patients experiencing long waits have had biopsies and diagnoses, and are waiting long periods for surgery.
Prostate Cancer Foundation chief executive Graeme Woodside said some prostate cancers grew much more aggressively than others.
If it spread from the prostate gland, it became serious and difficult to treat, he said.
"It eventually will have life-threatening consequences. I’m concerned about the significant delays.
"We’re not just talking one or two months, we’re talking five- and seven-month delays [for surgery after diagnosis]."
Under an official target, cancer patients with a diagnosis should be treated within 31 days of the decision to treat them. SDHB chief executive Chris Fleming apologised to affected patients and said in a statement the DHB was "committed to making improvements and providing them with certainty regarding their care".
"An external review has been undertaken of the urology service to gain a clearer understanding of the service and identify opportunities for improvements.
"In the interim, Southern DHB is exploring more immediate options for those patients waiting now, the chief executive and chief medical officer will be meeting with the urologists to discuss how to move both the immediate challenges and the issues which are identified in the review, forward," Mr Fleming said.