In the sentence extracted from biomedical literature, identify all the disease entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="disease"> to denote a disease.

### Input Text: We have used this technique to analyze BRCA1 in 162 families with a history of breast and / or ovarian cancer and identified 12 distinct mutations in 35 families . .
### Output Text:
We have used this technique to analyze BRCA1 in 162 families with a history of <span class="disease">breast and / or ovarian cancer</span> and identified 12 distinct mutations in 35 families . . 