Polyurethane polytech implants linked to cancer? Now extremely nervous for my breast augmentation next week

While the jury is still out there is concern surrounding textured devices and Breast Implant Associated Anaplastic Large Cell Lymphoma:
The following FAQ was released by ASAPS (American Society of Aesthetic Plastic Surgeons) on the topic of BIA-ALCL:
The Food and Drug Administration (FDA) has recently updated the public information on its website about breast implant associated anaplastic large cell lymphoma (BIA-ALCL). We have known about this disease for quite some time and the FDA has been providing updates since 2011.
1. BIA-ALCL is a rare form of lymphoma that develops adjacent to breast implants • Because it is rare it is difficult to be certain about the absolute risk. • The current risk is estimated to be 1 in 30,000. However, to date there has never been a documented case in a patient with only a smooth implant.
2. BIA-ALCL is not breast cancer • The risk of developing breast cancer is about 1 in 8 women
3. What are the symptoms of BIA-ALCL in women with breast implants? • The most common symptom is a persistent swelling of the breast • Can include other symptoms such as a lump in the breast or armpit • These symptoms develop between 3 and 14 years following the insertion of breast implants and most commonly around eight years. • The swelling of the breast is due to fluid accumulating around the implant
4. Are all implant types associated with BIA-ALCL? • ALCL has not been identified in women who have only had smooth implants. • The disease is associated with textured implants.
5. How is BIA-ALCL diagnosed? • In patients with a fluid collection around the implants and ultrasound should be performed to exclude the diagnosis • At the time of ultrasound examination and needle is inserted to drain some fluid which is then tested.
6. How is BIA-ALCL treated? • Most women who are diagnosed with this disease are treated by the removal of both implants and the fibrous capsule around them and this is complete treatment. All known cases where there were no delays in diagnosis have resulted in 100% cure at this time.
7. Can breast implants be inserted again if I have BIA-ALCL? • Yes. Smooth implant have been replace at a delayed interval in treated patients as well as immediately in some cases.
8. Where can I get more information? FDA.gov, Surgery.org, plasticsurgery.org
Shaped implants are textured in order to counter the potential for malrotation. A shaped device must be placed in a particular orientation (otherwise the appearance is bizarre). The texture on the device acts as a sort of velcro holding it in place. Meticulous pocket dissection is a must as a roomy pocket will allow for movement in the early post operative period and the velcro will ensure that it stays that way. This is not a concern for round devices as they are round no matter the orientation. 
Manufacturers are now offering round devices with the same form stable gel as offered in the shaped gels (without the concern for malrotation). These are only now becoming widely available.
With regards to your specific question, in my practice a smooth round cohesive gel implants is my default in cosmetic patients. A submuscular round device will assume a more tear-drop shape when placed into the pocket due to the pressure across the upper pole. That being said, the benefits to a cosmetic patient gleaned from a form stable implant are, in my opinion, negligible. The cost difference, on the other hand, is significant. Ultimately, for a myriad of reasons (in most cases) I see no reason to advocate for textured shaped devices. The news regarding BIA-ALCL has only served to reinforce this tendency.
As always, discuss your concerns with a board certified plastic surgeon (ABPS).

I am not aware of any FDA approved polyurethane covered implants approved for use currently in the USA. Are you referring to textured silicone implants currently available that have been associated in a rare form of lymphoma called breast implant associated ALCL or BIA-ALCL. These are not polyurethane covered, but just a textured silicone shell. This cancer is extremely rare and a specific cause and effect has not been clearly established yet. 

Thank you for sharing your question. A patient should not go into surgery worried and anxious about possible complications that they read online and I would advocate seeing your surgeon to voice your concerns.  They should be able to help answer and address your concerns.  Best wishes.

I would suggest going back to your surgeon and discussing all your concerns. You should be excited about your decision and not worried about cancer.