lapatinib based treatment
lapatinib plus fulvestrant lapatinib plus letrozole
la/mBC - HR-positive - 1st line (L1) 13      
la/mBC - HR positive - L1 - PIK3CA mutant 1
Comparator:  vs fulvestrant;   vs letrozole; 
Risk of bias:  low;   some concerns;   high;  NA;