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  • Writer's pictureCynthia Chin-Lee

Chihiro Hozumi: "Cancer is controllable."

Updated: Jul 3, 2023

Note: I'm interviewing members of the Nutritional Oncology Research Institute (NORI) support group.

Photo of Robert M. Hoffman and Chihiro Hozumi
L: Robert M. Hoffman and Chihiro Hozumi in San Diego 2023

When Chihiro Hozumi joined AntiCancer Japan in 2015, little did she know that she would one day benefit from the technologies of her own company. Born and raised in Japan, Chihiro developed her English fluency while studying at Washington State University in Pullman, Washington. Leveraging her communication skills, she worked as an inflight interpreter for United Airlines in Narita, site of Tokyo’s international airport. Chihiro’s language skills would come in handy later as general manager for AntiCancer Japan, a branch of the company AntiCancer, Inc. based in San Diego, CA, and founded by pioneering cancer researcher, Robert M. Hoffman, PhD.

Neither a scientist nor a medical doctor, Chihiro has learned a lot about cancer research and mouse models through her work. She even invented a way to engraft patient tumors into mice as a way to research their responses to drug treatments. At age 59, she went for her annual medical check-up and was shocked that she had invasive lobular carcinoma (ILC), a less common form of breast cancer.

Chihiro Hozumi's cancer at a glance

Cancer: Breast cancer, invasive lobular carcinoma, stage 3 Age at diagnosis: 59 Surgery, radiation, chemo, hormone treatment? Mastectomy and restorative surgery (left breast), chemotherapy (doxorubicin with cyclophosphamide), Arimidex (hormone blocker/aromatase inhibitor) earlier and now Femara (Letrozole) Other treatments: low-methionine plant-based diet, nutraceuticals (sodium selenite), methioninase, VerzenioR (used with hormone blocker to prevent recurrence) Tracking strategies: Methionine PET scan (MET-PET), carcinoembryonic antigen (CEA) blood marker tests Quotes: “I’m proud to be proof of the synergy between methioninase and chemotherapy."

She exclaimed, “Omigod, my family never had cancer and my mother was so worried.” As the name ILC suggests, cancer forms in the milk-producing lobules which may be harder to detect because it often does not form a distinct lump like the ductal cancer that make up over 80 percent of breast cancers. Chihiro decided to have a mastectomy with reconstructive surgery at the same time, enduring 12 hours on the operating table and recovering for 9 more days in the hospital. However, she said no to chemotherapy, hoping the surgery to remove the 8 cm tumor and the hormone blocking drugs would take care of the cancer.

map of Japan
Map of Japan

Dr. Hoffman recommended Chihiro have a methionine positron imaging tomography scan (MET-PET) to monitor her cancer, which is available in a clinic in Japan, but not covered by insurance. The MET-PET scan could image her cancer more precisely than the traditional glucose (sugar) PET. The MET-PET is better than a glucose-based PET scan because cancer cells are addicted to the essential amino acid methionine. The differential between the normal cells’ need for methionine and cancer cells’ need for methionine is greater than the normal cells’ need for glucose and the cancer cells’ need for glucose. Cancer cells addiction to methionine is called the Hoffman effect, named for Robert Hoffman, AntiCancer’s chief executive and Chihiro’s manager. Chihiro admits, “I didn’t take him seriously. I felt I should have listened.”

Chart showing dramatic decline of CEA markers from Feb to May 2022
Chihiro's CEA markers decline with methioninase and chemotherapy

She monitored her condition every 2 months and unfortunately after 2 years, the cancer returned to her lymph nodes under her arm in an area so big and deep, a second surgery would have been impossible. She says, “I was really furious that the cancer came back and metastasized.”

With the recurrence, Chihiro took her treatment more seriously, including four areas:

  • Doxorubicin chemotherapy

  • Methionine-restricted diet

  • Sodium selenite from NORI (Nutritional Oncology Research Institute)

  • Methioninase, an oral supplement from AntiCancer Inc that degrades methionine in the body

Scan of lymph node cancer before and after treatment
Computed tomography (CT) scan of lymph node cancer. Left shows 3 months before treatment. Right shows 3 months after the start of treatment.

No more fish, eggs, or meat but a bounty of fruits and vegetables for her. Many Japanese dishes are not meat or fish centered so Chihiro says, “If I join friends at a restaurant, I can pick out the meat and just have the vegetables in the stir fry.” She has confidence in her treatment plan as she had read the many studies Dr. Hoffman has published. “I look at the facts. The numbers are telling me that the methioninase and chemo are working. My ILC (invasive lobular carcinoma) usually has a poor response to chemo, less than five percent. I’m very lucky to have methioninase, the methionine-restricted diet, and chemo. They all worked together.”

Japanese stir fry photo
Japanese stir fry with meat; Chihiro picks out the meat to stay plant-based!

After about two and a half months of the new treatments, Chihiro's tumors disappeared by 80 percent. Doxorubicin and cyclophosphamide chemotherapy were started in March 2022. Through the MET-PET, her medical team could not detect cancer, but her surgeon still wanted to do surgery. Chihiro refused. She says, “Even if I had surgery, the chances are not 100 percent certain.” With the diet, methioninase and chemotherapy, Chihiro says, “Cancer is controllable.”

Even Dr. Hoffman was surprised at how well the combination therapy worked. Chihiro's senior surgeon told her that invasive lobular carcinoma usually does not respond well to chemo. Chihiro says, “I’m proud to be proof of the synergy between methioninase and chemotherapy.” For those curious about the scientific details, see this paper published in the journal Anticancer Research in December 2022 by Dr. Yutoro Kubota and others.

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2 комментария

10 июн. 2023 г.

So nice to read a real story and successful one at that.


Cynthia Chin-Lee
Cynthia Chin-Lee
08 июн. 2023 г.

Thank you, Chihiro Hozumi, for our Zoom interview.

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