The interaction between lung cancer metastases to the brain and their surroundings

due to the fact that an interrelation between metastases of lung cancer to the brain and surroundings may influence the prognosis, we made attempts to answer the following questions: 1) how is the border between the tumour and its surroundings formed? 2) are there any differences in the glial and vascular reactivity around different forms of lung cancer metastases to the brain?

a neuropathological examination has been done on 66 patients (27 women and 39 men) with lung cancer metastases to the brain. They were divided into three groups: group I - 18 cases of squamous cell lung cancer (sqclc), group II - 33 cases of lung adenocarcinoma (adl) and group III - 15 cases of small cell lung cancer (sclc).

the most "aggressive" mode of metastatic infiltration into the brain was presented by sqclc. In many cases of the sqclc the end of neoplastic infiltration exceeded the area of the examined specimen, represented the material taken during the routine neurosurgical procedure (mean distance 153.8 microm compared to group II and group III cases: 56.10 and 26.09 microm respectively, p<0.05). The highest intensity of astroglial reaction was found around group III tumours (the mean number of astrocytes 48.15 SD+/-8.25 per measured area in comparison with 24.76 SD+/-10.54 and 19.75 SD+/-4.26 around group III and II metastases, respectively p<0.05). A remarkable fibrillary gliosis was also found around group III cases while the smallest one, comparable with normal nervous tissue glia immunoreactivity, within surroundings of group I metastases: group III : II p=0.0098, group III : I p=0.0000 and group III : control tissue p=0.0000). There were no significant differences in the mean number of vessels within the metastatic surroundings.

a dispersed mode of infiltration by sqclc metastases to the brain causes precise detection of the macroscopic border between the metastatic tumour and the nervous tissue to be much more difficult than in sclc, which is sharply demarcated from the surroundings. The poor prognosis in sqclc metastases to the brain may, among other, depend on metastatic remnants in the form of dispersed neoplastic cells within the seemingly uninvolved nervous tissue, not removed during neurosurgical procedures.