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: R841W is likely to be an etiologically significant lesion with involvement in close to 1 % ( 95 % confidence interval of 0 - 1 . 7 % ) of all breast and ovarian cancers in this population .
### Output Text:
R841W is likely to be an etiologically significant lesion with involvement in close to 1 % ( 95 % confidence interval of 0 - 1 . 7 % ) of all <span class="disease">breast and ovarian cancers</span> in this population . 