Bone cancer prognosis

Purpose: Bone scan has been widely used for early detection of bone metastasis but its low specificity complicates confirmation of bone scan findings. Therefore, radiologic studies or bone biopsy are often needed to confirm the abnormalities on bone scans. However, in patients whose management will not be significantly altered by the demonstration of bone involvement, special studies such as MRI or bone biopsy may be time consuming, and not cost-effective. And in patients who has multiple areas of uptake, it is difficult to perform these special studies. To provide guidelines in the interpretation of bone scan abnormalities which were not yet evident on plain radiographs, we retrospectively analyzed the effect of abnormal bone uptakes on the prognosis of patients with primary lung cancer.

Methods: The records of 408 patients who were diagnosed as primary lung cancer between January 1995 and December 1996 reviewed retrospectively. After we confirmed that more than two abnormal bone uptake was a significant prognostic factor, we compared the survival of stage I-IIIB with more than two abnormal bone uptakes (potential stage IV, group A) to that of stage IIIB patients with no abnormal uptake (true stage IIIB, group B), and that of stage IV patients with no abnormal uptake (true stage IV, group C).

Results: The overall survival of patients with abnormal bone uptake was not significantly different from those without abnormal uptake. However, the patients with more than two abnormal bone uptakes had significantly shorter survival than those with no abnormal uptake (p [is less than] 0.05). Group A revealed shorter survival than group B (p [is less than] 0.05). But there was no significant difference of survival times between group A and group C.

Conclusion: These results suggest that one or two abnormal bone uptake at diagnosis did not affect overall survival of the patients. The patients with more than two abnormal bone uptakes are considered as clinical stage IV because of high probability of bone metastasis.

Clinical Implications: In patients whose management will not significantly changed by the demonstration of bone metastasis, it would be better to consider three or more areas of abnormal bone uptakes on bone scan as clinical stage IV.

Supported by: KOSEF through the Biomolecular Engineering Center at KNUH.

Jae-Yong Park, MD(*); K Y Kim, MD; J Lee, MD; S Cha, MD; S C Chae, MD; C H Kim, MD and T H Jung, MD. Internal Medicine, Kyungpook National University Hospital, Taegu, Korea, Republic of.