Chemotherapy is very often lifesaving or at least life-prolonging. However, there are some long-term side effects (see below):

• Dental problems
• Early menopause
• Hearing loss
• Heart problems
• Increased risk of other cancers
• Infertility
• Loss of taste
• Lung disease
• Nerve damage
• Osteoporosis
• Reduced lung capacity

List copied verbatim from mayoclinic.org.