Regarding teriparatide and breast cancer, this is what Google AI summarizes. Do not assume this is the definitive answer but it may be helpful:

"Teriparatide is an osteoporosis treatment that promotes bone formation and has been shown to be safe in breast cancer models, not causing tumor growth or bone destruction. It may be beneficial for patients with breast cancer who are at risk of osteoporosis due to their treatment.
uspharmacist.com BioMed Central
Teriparatide and Breast Cancer
Overview of Teriparatide
Teriparatide (TPTD) is a medication primarily used to treat osteoporosis. It works by promoting bone formation and is often considered for patients at risk of fractures.
Safety in Breast Cancer Models
Recent studies indicate that teriparatide may be safe for use in patients with breast cancer, particularly those with bone metastases. Research has shown that TPTD does not promote tumor growth or cause bone destruction in breast cancer models. This suggests that it could be a viable option for managing bone health in breast cancer patients, especially since treatments for breast cancer can increase the risk of osteoporosis.
Impact on Bone Health
Breast cancer treatments, such as chemotherapy and hormone therapy, can lead to decreased bone density and increased fracture risk. Teriparatide's ability to stimulate bone formation may help counteract these effects, making it a potential therapeutic option for maintaining bone health in women undergoing breast cancer treatment.
Conclusion
Teriparatide shows promise as a safe treatment for improving bone health in breast cancer patients, particularly those with bone metastases. Its role in managing osteoporosis in this population is an important area of ongoing research.
uspharmacist.com
Wikipedia"