From a clinical trial report:

enter image description here

I think that Ps stands for parasternal (nodes) but what could Sp mean?

I haven't found a mention of "Sp" in the literature by googling for about 20 minutes.

P.S. Got some tentative googling results. Could it be "superior phrenic nodes"? Or "segmental pulmonary" area? (I conducted Google searches using "Breast cancer"+"Ps", "Chest wall"+"Sp" etc. in different combinations and looked into research articles related to breast cancer and its metastases).

  • 1
    I don't have an answer for you re: Ps or Sp. They are not standard abbreviations, but I do not think they refer to nodes. This section of the table appears to be a list of 7 locations for a recurrence of tumor (and a given patient may have more than one site of recurrence). You have breast/chest wall recurrence (preserved breast ax, chest wall, and contralateral breast ax, and then common sites for distant mets (liver, lung, bone). Nodes are in a different location in the table.
    – De Novo
    Jan 28, 2019 at 17:25
  • 2
    Agreed these are not standard abbreviations. Typically papers should explain their abbreviations somewhere, even if they are standard ones, but I guess not in this case. Subpectoral and parasternal would be my most educated guesses, but those are guesses only.
    – DoctorWhom
    Jan 28, 2019 at 23:07
  • I recently joined this community and don't have enough reputation to comment, so I'm putting this in an answer. I agree that Ps and Sp are tough to pin down without a key to abbreviations. The paper that you site has a key for every other figure, but it is missing in the one you have posted on. You could write to the journal and ask for an answer, they may even fix the mistake if it is indeed a mistake. As for the paper, it is clearly looking at a cohort of HER2 positive patients and the location of recurrence. Most clinical anatomists (like myself) teach that the breast is divided into four q Feb 5, 2019 at 7:53
  • Thank you! I wrote a letter to one of the authors, and unexpectedly got a prompt response. Feb 5, 2019 at 10:26
  • Outstanding question and answer!
    – Carey Gregory
    Feb 6, 2019 at 6:39

1 Answer 1


Mr. Hiroyasu Yamashiro wrote an anwer:

Thank you for your question about the paper. The meaning of the abbreviations you ask is as follows. Thank you.

Sp - Supraclavicular lymph nodes
Ps - Parasternal lymph nodes

Hiroyasu Yamashiro

  • 4
    Thanks for updating this with the answer from the source!
    – De Novo
    Feb 5, 2019 at 18:13
  • 1
    Can the mods please un-community wiki this post? A community wiki is a collaborative effort of multiple users to create an answer, (and everybody should expand said answer); thus it belongs to no one in particular but the community. // In this case, it clearly is a research effort by CopperKettle and I do not see why this should not be their tribute and thus their post. A community wiki also has the image of an ever expanding/updating post, while this answers the question perfectly. @CopperKettle Take your well-deserved rep :)
    – Narusan
    Feb 6, 2019 at 23:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.