Is there possibility of bone metastasis occurring if primary carsinoma cancer, stage 1b, grade 2 of the breast full mastec recon sentinel nodes clear?

Unlikely but poss. Prognosis of small stage i intermediate grade tumor is favorable esp . Er+. For er- (triple neg or her2+) tumors a bit worse but still favorable in stage i. Recurrence (local or distant) is not unheard of. While lymphatic/nodal spread is the most common, there are other ways for tumors to spread. Also while most sent. Nodes are in the axilla, tumor can drain elsewhere (supra clav, int mammary).
Yes. Any invasive cancer has the potential to spread to the bones or any other organ. A stage i cancer is not likely to spread but it can happen. Talk to your cancer doctor about any abnormal symptom you may have. Is important to be aware but not to live in fear. Best to you.