Since studies regarding the effect of polysomy 17 (P17) in breast cancer cases in some clinical findings are few in number and are in small sample sizes, during the meta-analysis the effects of P17 in patients without amplification on lymph node involvement, estrogen receptor, progesterone receptor and immunohistochemistry were examined. With the aim of researching into the effects of P17 in breast cancer patients, by using the keywords "polysomy 17 breast cancer", the Pubmed literature database was scanned up to June 2017 and 141 studies were accessed. For research into the impact of P17 on immunohistochemistry, lymph node involvement, estrogen receptor, progesterone receptor in breast cancer patients through meta-analysis, 14 of the publications examined were found to be suitable. In cases of publication bias, the trim and fill method was applied. In cases where heterogeneity was determined in the publications the DerSimonian-Laird method was carried out using the random effects model, while when there was homogeneity in the publications, the Mantel Haenszel method was applied using the fixed effects model. As a result of this study, it was observed that in lymph node involvement, P17 was a risk factor in patients without amplification(OR=1.84, p=0.001). P17 wasn't a risk factor on estrogen and progesterone receptor in patients without amplification (OR=0.94, p=0.875; OR=0.83, p=0.387). In terms of immunohistochemistry (IHC) levels, it was observed that P17 was a risk factor for immunohistochemistry increase in patients without amplification (IHC[2+, 3+]/IHC[1+, 2+, 3+] OR=6.15, p<0.001; IHC[2+]/IHC[1+, 2+] OR=3.06, p=0.002; IHC[3+]/IHC[1+, 3+] OR=19.92, p<0.001; IHC[3+]/IHC[2+, 3+] OR=8.29, p<0.001).