A case of stage IV HER2-positive invasive ductal carcinoma explores the use of a ketogenic, very-low-carbohydrate diet alongside conventional cancer therapy, highlighting the potential roles of metabolic health, nutrition, and lifestyle in comprehensive oncology care.
This unique case study highlights the importance that diet and lifestyle plays in supporting conventional chemotherapy in this rare turnaround of advanced stage 4, breast cancer (IDC) with metastasis to the lymph nodes, lungs, liver and bone. This study showcases the healing power of our most basic and foundational naturopathic therapies, “let food be thy medicine, and medicine be thy food,” coined by Hippocrates, humbly witnessed by me here.
Invasive or infiltrative ductal carcinoma (IDC) is the most common type of breast cancer, making up 80% of all breast cancer diagnoses. IDC occurs when cancer cells that begin forming in a milk duct of the breast spread beyond the duct into other breast tissue or to other areas of the body. This contrasts with Ductal Carcinoma in Situ (DCIS) which is non-invasive breast cancer, forming and remaining contained within the milk duct without spread to any other areas of the breast or elsewhere in the body.
In considering risk, she lacked various genetic risk factors associated with diagnosis of IDC. She did not have dense breasts, her mammography categorized her breast density as category B; she was well below the age of 55; she was Caucasian versus African; however, she did have a very strong family history of reproductive cancers. In fact, she had a paternal aunt with breast cancer; a maternal grandmother, maternal aunt, and maternal great grandmother all with ovarian cancer. However, her genetic testing showed no mutation in the BRCA 1 or 2 genes.
It is known that lifestyle and environmental factors do increase the risk of IDC, especially lack of physical activity, poor diet, being overweight or obese, smoking and/or drinking alcohol. Upon investigation, it was noteworthy that this patient did exhibit all these lifestyle risk factors.
“I went back to our core naturopathic principles, the healing power of nature, identify and treat the cause, treat the whole person, and doctor as teacher.”
Dr. Sachdev’s Case Study of “Annie”
While working in naturopathic oncology and women’s health, seeing countless patients day in and day out, it can be daunting to have advanced cancer patients walk through your door and feel the weight of their expectations for your treatments being their last-ditch efforts in staving off disease progression and prolonging life expectancy. I certainly felt this way when “Annie”, a lovely 34-year-old female patient – married with 2 very young children – walked into my office in fall of 2021 diagnosed with stage 4, right-sided IDC breast cancer (estrogen and progesterone negative, HER2/neu positive). The cancer had already spread to her lymph nodes, lungs, liver, and bone at the time of her initial diagnosis in July & August 2021, when she first sought medical treatment for breastfeeding challenges and a palpable breast lump, which is a common and typical initial presentation.
Following her preliminary investigation at the hospital, Annie’s core biopsy in early July 2021 was positive, and her breast ultrasound showed an almost 7 cm lesion (the larger one of two lesions) in her right breast, for which she was fast tracked to a conventional oncology team who began neoadjuvant chemotherapy on July 28, 2021 with Adriamycin (Doxorubicin) and Cytoxan (Cyclophosphamide), aka AC.
After, treatment she underwent a staging CT and bone scan on Aug 17, 2021 and Aug 31, 2021, exposing multiple pulmonary nodules ranging in size (all under 1 cm), multiple liver lesions ranging in size up to 1.7 cm, and osseous metastasis to her hip and spine, leading to an adjustment her drug therapy protocol to weekly paclitaxel (Taxol) beginning on Aug 31, 2021, in addition to trastuzumab (Herceptin) + pertuzumab (Perjeta) + paclitaxel (Taxol) every 3 weeks, which she had begun Aug 24, 2021.
The timing here is noteworthy.
Annie came to my naturopathic clinic on Sept 1, 2021, seeking a naturopathic and integrative approach to manage what she had been told was “incurable” cancer. She was interested in making dietary and lifestyle changes and wanted to consider additional supplement recommendations for her PMOS/PCOS (Hx of infertility and IVF) and obesity, admittedly due to unhealthy eating patterns and food choices including regular consumption of high sugar, processed, and “fast” foods. She reasonably hoped for improved quality of life, reduced side effects of conventional treatments, and management of disease wherever possible.
When she came to see me, she had already begun making some dietary changes including: instead of eating take out for most of her meals and regularly consuming sweets, chocolate, baked cookies, chips, “junk food”, and cups coffee with milk & sugar, she began cooking at home more often, eating more whole foods, and incorporating fruits and vegetables while cutting back on sweets and processed “junk” foods.
As I sat with Annie and her family, listened to her story, and took in the gravity of her case, I felt compelled to offer a slew of therapies, but here was a woman new to the concept of wellness, healing and how her choices affected her health. I went back to our core naturopathic principles, the healing power of nature, identify and treat the cause, treat the whole person, and doctor as teacher [1]. Therefore, instead of making multiple various supplement or therapy recommendations, I decided to focus on giving her my best dietary and nutritional advice.
Having worked in brain injury and seizure disorders as a pediatric registered nurse earlier in my health career, I was familiar with using the ketogenic diet in brain dysfunction. Through my experience as a naturopathic doctor working in naturopathic oncology, I rarely considered it be used widely for cancer care, having only used it a small handful of times in advanced cancer patients [2]. Additionally at that time, research supporting the use of ketogenic diets mainly focused on seizure disorders and central nervous system (CNS) tumors [3, 4, 5] and was limited for widespread use in other cancer types [6].
With the preclinical evidence that “certain cancer cells exhibit reduced capacity to utilize ketone bodies due to impaired ketolytic enzyme activity”, this led to the hypothesis that carbohydrate restriction may create a metabolic environment less favorable for tumor growth [7]. Based on the evidence that “carbohydrate restriction can reduce postprandial glucose excursions and improve glycemic control” and “as a potential dietary strategy for improving metabolic regulation in patients with type 2 diabetes” [8], and since “chronic hyperinsulinemia and insulin resistance have been implicated in tumor progression and cancer-related metabolic dysregulation” [9,10], I counseled her on eating low glycemic index foods and prescribed the ketogenic diet as a metabolic strategy to reduce circulating glucose levels and insulin signaling while establishing and maintaining prolonged ketosis. I also instructed her to purchase urine testing ketone strips, monitor her macronutrient intake using a diet app, and modify her carbohydrate intake to maintain daily ketosis.
What happened next felt like a miracle.
We did a short follow up to check-in one week later on Sept 9, 2021. She noted that in order to maintain ketosis, she needed to consume fewer than 25 grams of carbohydrates per day. Furthermore, over the past week, she reported having noticed some breast changes immediately upon starting the new diet.
Our next naturopathic consult took place on Dec 9, 2021. We reviewed her hospital notes which were as follows: on Sept 13, 2021, it was noted that her right breast mass had almost completely resolved with no palpable mass, her nipple was no longer inverted and became more normal in shape, her nipples had gone through a cycle of having been dry, then peeling, and then became normal with a color change from previously dark to normal. She even began growing back some of her head hair, eye lashes and eye brows despite continued regular chemotherapy. On Nov 16, 2021 she underwent a full body CT scan which showed that her right breast mass had reduced in size, many of her lung and liver nodules had either fully resolved or reduced in size, her osseous lesions were healing, and she no longer had any lymphadenopathy.
When we followed up on March 9, 2022, she was not strictly following the ketogenic diet nor measuring her urine ketones, but she was maintaining a very low carbohydrate diet (total carbs 25-35 grams / day) having introduced some berries and other low carbohydrate whole foods occasionally. Annie performed a CT scan on Feb 28, 2022, showing continued improvements in all areas with no new lesions. She still had some lung and liver lesions, but they improved from her previous imaging. Since her energy was good and she was responding to and tolerating her medical treatments well, I recommended she begin 30 minutes of walking daily and continue the ketogenic diet.
During our follow up on May 18, 2022, Annie reported good energy with minimal side effects of chemotherapy treatment, allowing her to live what she described as a “fairly normal life”. Her head hair had mostly grown back, she had a new outlook on life, and she was ready to continue enjoying it. She was doing her best to follow general principles of healthy eating and was walking 30-40 minutes at least 5x/week. Additionally, due to some recent reactions from her weekly paclitaxel, she stopped paclitaxel therapy in April 2022 and continued with trastuzumab (Herceptin) + pertuzumab (Perjeta) only every 3 weeks. Her ongoing CT scans were scheduled q 3-6 months.
Fast forward to March 20, 2026, when to my pleasant surprise, Annie returns to my office. She continued to have mostly stable breast cancer with stable or improving lymph nodes, lung, liver, and bone metastasis. However, despite no worsening disease evidenced in her diagnostic imaging reports, she was diagnosed with brain metastasis of her primary cancer in July 2025 after the sudden appearance of headaches for which she underwent successful surgery and radiation. We reconsidered the merits of ketogenic diet [11] given the context of known benefit in CNS tumors and breast cancer [12, 13, 14, 15, 16]; however, since Annie found this too restrictive, we reviewed the Canada Food Guide 2019 and in keeping with current guidelines recommended the highly researched and evidence-supported Mediterranean Diet [17].
Following up on May 21, 2026, Annie is doing her best to get back to being healthy and being conscious of how she plates her food. She is meal prepping and eating three meals/day, spreading meals evenly throughout the day, without snacking. She walks daily upwards of 45-60 minutes / day. She has even started doing workout videos from Instagram/YouTube, and aspires to become strong enough to be a runner. We discussed the importance of incorporating adequate daily protein, fiber and potential supplementation to meet her needs. She is motivated to maintain a lifestyle and dietary approach that can last a lifetime.
Annie and I marvel at the role that diet and lifestyle changes have played in her health journey and I look forward to walking this path alongside her as we remain hopeful for a bright future for her and her family.
Conclusion & Caution
Despite Annie’s triumph, upon review of the current and up to date literature, I do NOT widely recommend the long-term application of the ketogenic diet to all patients for all types of cancer. In fact, a systematic review and meta-analysis of randomized control trials published in 2024 suggests that observed benefits of the ketogenic diet in cancer patients may actually come from improved metabolic indicators such as glucose and insulin regulation, reduced inflammation, and improved body composition rather than from improved cancer tumor cell metabolism [18]. This is the most plausible explanation for Annie’s success since she also had concomitant PMOS (formerly PCOS). Additionally, considering data to date regarding the long-term safety of overly restrictive low-glucose diets in cancer care are mixed, and given the related risk of ketones upregulating and driving metastasis, research is ongoing and inconclusive [19]. Therefore, naturopathic doctors must keep abreast of the latest data and make informed decisions regarding individualized patient care focusing on core naturopathic principles of tolle causam and treating the whole person and highlights the nuance and complexity in managing and treating cancer.
