My wife was diagnosed with cancer of unknown primary in March

Im not familiar with that particular cancer.
For consideration you might be interested in watching Dr. Thomas Seyfrieds interviews online. He's a professor at Boston College.
His belief is that cancer is metabolic and not necessarily genetic.

A good layman's book is Keto for Cancer By Miriam-Kalamian.
Its an excellent read and a different approach for treatment.
Dr Thomas Seyfried had written the forward to the book.

Blessings to you and your wife.

The best thing you can do is to engage with a large hospital dedicated to treating cancer. They have the experience, the protocols, the required technologies and most importantly the full range of capabilities to treat the cancer and the related side effects. Good lick

In California i am at the City of Hope in Duarte. I agree with the previous post. Find the local research cancer hospital. Check their websites for who to contact. The internet is a dark place. Reputable. Mayo Clinic will come up in the search engines. MD Anderson and so many more. Keep us posted. I know more people will post after me.

@umeshghimire

You wrote "retroperoneal area". Would you mean retroperitoneal? You are asking about chemotherapy treatment protocol. Do you have access to the pathology report? It is the pathologist (physician) who examines tissue and specimens under the microscope and provides a diagnosis of the kind of cancer. Peritoneal refers to the location (the tissue that is the lining for the wall of the abdomen) but not the type of cancer cells that the pathologist writes about in their report.

It sounds like cancer was found from lymph node biopsy and then in the peritoneal area. The doctors believe that there is a primary cancer somewhere else but they haven't located it. Is that correct? They are treating your wife's cancer as if it is a "secondary cancer" meaning the cancer may have originated somewhere else.

Here is a link that describes cancers related to the peritoneum:

MD Anderson: Peritoneal Cancer

-- https://www.mdanderson.org/cancerwise/peritoneal-cancer--8-questions--answered.h00-159697545.html

Is your wife interested in getting another opinion? If yes, here is a link to the National Cancer Institute's NCI) Designated Cancer Centers. You might like to look through this page and locate the NCI closest to where you reside. These centers have ongoing research and clinical trials.

NCI-Designated Cancer Cancer Centers:

-- https://www.cancer.gov/research/infrastructure/cancer-centers

Do my questions, resources, and comments help?

Retroperitoneal is different than the peritoneal & perineum. It is the space located behind the peritoneum, which is the membrane that covers the abdominal wall & covers most abdominal organs. Kidneys live in this space, for example. I was a diagnostic medical Sonographer for 30years. Hope that helps.

I was diagnosed & treated for a stage IV unknown primary tumor in 3/21, in 2/23 my primary showed up, & I went through the targeted protocol. Scans have shown no evidence of new disease since 4/23. We went to MD Anderson midway through the first treatment. Personally, I had a terrible experience with them, & they had nothing different to offer. The doctor hadn’t even looked at my case (even though they shared the same reporting system as my hospital, & had gotten access to all my files 6 weeks earlier), & wasted the appointment criticizing my doctor for not running tests, he had run. My husband spent the time pulling up reports & showing him the results. At the end of the appointment, he said “well, your resent scan shows that treatment is working, we have nothing more to do at this time, but come here when it returns, because we are much more advanced.” I live in a metropolitan area with 3 large cancer centers. In my opinion (hind site is everything), I would wait to see what the scans show, before getting a second opinion. I am in very good hands with my medical team. If you are not, after the treatment is finished might be the time to change?
I hope this is helpful & not just more confusing. I always hesitate to tell my experience, because they are all unique. Best of luck to you & your wife.❤️

I agree wholeheartedly with @katgob’s last post. Folks at City of Hope who have given excellent care to two people in my circle and MD Anderson, where my family member received wonderful, innovative treatment and care are the type of facility that can get to the bottom of the problem. I have been seen at Mayo for a non-cancer related diagnosis and am impressed by the professionalism and precision with which they uncovered my issue, which has been completely and satisfactorily resolved. Go to the best. You will not be sorry.