[The relationship between chemotherapy and multidrug resistance of lung cancer].
BACKGROUND
To investigate the relationship between multidrug resistance(MDR) and chemotherapy and the possibility of P-gp as a clinical prognostic indicator.


METHODS
P-gp, MDR1 gene product, was detected in 66 cases of relapsed lung cancer patients after chemotherapy and 131 lung cancer patients with no prior chemotherapy by immunohistochemistry.


RESULTS
The expressive level of P-gp in relapsed group after chemotherapy was much higher than that of non-chemotherapy group (P<0.05). A significant difference of P-gp expression existed between before and after chemotherapy for squamous cell carcinoma and SCLC (P<0.05), but not for adenocarcinoma. In non-chemotherapy group, lung cancer tissues with different histological types had different P-gp positive rates, which were adenocarcinoma, squamous cell carcinoma and SCLC in sequence from high to low (P<0.05). In relapsed group after chemotherapy, there was no significant difference among the three types of lung cancer (P>0.05). P-gp positive group had a significantly lower 3-year survival rate than negative group (P<0.05).


CONCLUSIONS
Chemotherapy may increase the incident rate of MDR in lung cancer. Adenocarcinoma is mainly primary MDR while SCLC and squamous cell carcinoma are mainly secondary to chemotherapy. P-gp expressive level can be used as a common clinical indicator for prognosis and chemotherapy in the patients with lung cancer.
Department of Pathology, Shandong University West Campus, Jinan, Shandong 250012, P.R.China.
G
G
Zhou
L
L
Wang
L
L
Guo
J
J
Zhen
K
K
Kakudo
H
H
Li