Page 2 of 2: who can answer that

qaz1009 · Credits: 683 My Scrapbook

Radiographically, metastatic prostate cancers are primarily osteoblastic but Osteoclast stimulation and activation are both present at a histologic level. Indeed, increased levels of markers of bone turnover, such as N-telopeptide and NTX, can be detected in the blood and urine of patients with progressing disease.Thus, the normal bone remodeling process is not uncoupled; rather, there is a shift in the balance in favor of bone growth. It is hypothesized that the resorptive process itself, under the direction of osteoclasts, promotes the release of factors that amplify the metastatic and invasive process. The protease action of PSA results in the activation of functional signaling molecules adjacent to tumor that further contribute to tumor cell growth and proliferation. For example, PSA cleavage of IGF, from its binding protein (IGFBP3), increases the local levels of a functional prostate cancer mitogen that is normally inactive as a bound complex. PSA can also activate parathyroid hormone–related protein, which inhibits osteoblast apoptosis.
Ref-Vincent DeVita 7th Edn 2004
hope this can help !

Akil · Credits: 27737 My Scrapbook

It should be remembered that there is NOT PURELY osteoblastic or osteoclastic process at an histopathological level as qaz1009 has rightly pointed. The clinical or the radiographic appearances are all due to the shift in the activity and balance of these processes.

This concept of osteoblastic or sclerotic and osteoclastic appearances is RESTRICTED to radiographic appearance. Because radiography is an INDISPENSABLE tool for diagnosis and analysis of bone metastasis. (I dont mean gold standard!)

The rule of the thumb:

In a patient with primary tumor, when he complains of bone pain or radiograph shows some differences. ALWAYS suspect bone metastasis unless proved otherwise without doubt. (rarely bone metastasis can actually present long after the initial primary tumor had been treated for eg kidney metastasis....though the reason for this latency in clinical manifestation is NOT very clear!)

Now to proceed with our differential diagnosis we go ahead with the actual radiographic appearance.....for eg breast cancer metastasis are both osteoclastic and osteoblastic, whereas prostratic cancers are predominantly osteoclastic and kidney tumors have a characteristic osteoclastic expansile appearance.

region predeliction (no specificity though!) for eg bone metastasis to upper limbs is rare excepting lung cancers which more than 50% are found metastasising to upper limb...etc!

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