Is it possible for the tumor to spread without lymph node involvement?

Question

Hello doctor,

My friend is suffering from metastatic liver disease. The primary site has been found to be the anal canal. The primary tumor was very difficult to find, as it was not visible on PET or colonoscopy. It was only felt on digital rectal examination.

Biopsy of the primary tumor as well as the liver lesions showed basaloid carcinoma. The histochemical examination showed synaptophysin positive, P63 and CK5/6 negative, and KI67 80% positive, and the histopathologic observation confirmed the basaloid tumor.

There is no affected regional lymph node and only distant metastasis to the liver. The doctor recommends starting with chemotherapy, and if it does not respond to it, then we can switch to Vismodegib afterward.

Though I am not an oncologist, I read a lot about cancer. Apparently, it is a rare tumor, and information is not really available about it. There are some doubts whether to start with preoperative chemotherapy and proceed with surgery or to remove both primary and secondary lesions and then to go for the chemotherapy or radiotherapy. As this is a rare tumor, every recommendation or suggestion would be valuable.

Is it possible to have a hematogenously spread tumor without lymph node involvement?
The PET describes the wall of the anus as thickened, with normal contours. Does it mean that locally it has not reached a big size?
No regional lymph nodes are affected, and colonoscopy showed a third-degree internal hemorrhoid. Is it possible that this is the site of entry of the metastasis?
Is it possible that the primary tumor is aggressive enough to metastasize but, being very close to veins, gave it an opportunity to spread distantly?

I know that I am just hypothesizing, but please share your opinion. It is so important to me to be sure about what we have to do. I will attach the PET scan and biopsy morphology.

Please help.

Thank you in advance.

Answer 1

Hi,

Welcome to icliniq.com.

Anal basaloid tumors carry the potential for metastasis, which can occur through three primary pathways, such as the escape of cancer cells into lymphatic vessels, venous drainage, or direct spread to adjacent organs.

In the case of your friend, metastasis transpired via cancer cells escaping into the venous drainage of the anal canal, subsequently reaching the liver and causing liver lesions. Notably, the tumor's size doesn't necessarily correlate with its metastatic potential. Despite its relatively small size, the tumor grew within the anal canal wall, eroding veins within the wall and allowing cancer cells to enter the venous drainage system.

Regarding treatment, chemotherapy aims to reduce tumor size, facilitating any subsequent surgery and aligning with contemporary organ preservation strategies embraced globally.

I hope it helps.

Thank you.