Today, she's waiting for an appointment with the surgeon to determine when her other breast will be removed, following signs of change in a recent mammogram.
"I have been very strong, I think you sort of find strength you didn't know was there, but it is being tested," Mrs Cotterill said.
An amazing group of friends and family were vital throughout her journey as they helped to pick her up when she was down.
Being proactive about any changes was something every woman could do and she fully endorsed regular check ups, as well as encouraging others to support various breast cancer charities.
"Oh gosh yes, it's so important, that's why you hear so much about it - they often don't get it early, it's one of the highest killers in New Zealand."
Mrs Cotterill leads a healthy life, eats the right foods and stays fit by cycling or playing golf.
In her case a predisposition to cancer came down to genetics - her mother also suffered from breast cancer at the age of 79, which later turned to bone cancer.
In Hawke's Bay alone, 140 women are diagnosed with breast cancer every year, many of whom are young and have aggressive forms.
About 25 per cent have to travel out of the region for treatment, while 10 per cent are obliged to head out of town for breast reconstructions.
Regardless of the type, a diagnosis throws lives into turmoil, disrupting work, family and often creating emotional and financial challenges.
The newly formed Hawke's Bay Breast Cancer Trust aimed to raise funds and awareness, as well as researching and educating local women and their families.
There are many ways in which people can help the Trust every day, including donations, sponsorship or joining in with 4.5km Breast Cancer twilight Fun Walks being held in Napier at the Sound Shell on Tuesday October 14 and Civic Square in Hastings the following day.
They are intended to be a celebration of life, time to remember and an opportunity to raise awareness for the disease.
People could win prizes by dressing in pink and registering at HBS Bank branches in Napier, Hastings and Havelock North, or on the day from 4pm.
• For more information see: funwalkshb.co.nz